I felt it important to mention the dangerous teachings of the charismatic movement, since this movement has become so prevalent today.  Each section will only summarise the doctrinal problems of this dangerous movement.  You will have to study each one in more detail if necessary.

Authority
We must begin at the beginning - "what is truth"?  If we don't know where the final authority is, then truth is what each of us decides it to be.  A Bible-believing Christian must settle the fact that the final authority for God's creation is what God Himself says in His Word.  (see Mathew 4:4; Luke 16:29-31; John 12:48 and John 17:17).

The charismatic movement is characterised by a floating authority.  Emotions, experiences, and dreams are very important in this movement and are often quoted as justification for certain non-Biblical actions or beliefs.  God says in His Word that truth is not open to "private interpretation" (II Peter 1:20).  However, charismatics are continually giving the Holy Ghost credit for their feelings or ideas, even if they disagree with the plain teaching of the Bible.  Emotions are not always right.  What we feel is not always true.  The heart cannot be trusted (see Jeremiah 17:9).  Always beware of statements like:  "God told me"; "God spoke to me"; etc.
Charismatics believe that Christians still possess the gift of prophecy.  If this were true, then the Bible would not be finished.  If this were true, what is spoken should be written down and added to the Bible, contrary to the very clear warning not to do so in Revelation 22:18-19.  When prophets of old spoke, God spoke through them what He wanted to say and it was recorded as His Word.  In the charismatic movement, prophecies are frequently given which contradict God's Word or don't come true.  God made it very clear that any prophecy which did not come true 100% was false (see Deuteronomy 18:20-22) and had been spoken by a false prophet.  Again, beware!
The ultimate deception of the last days and the tribulation will occur through "signs and wonders", according to God as spoken in His Word (see Matt 24:24; Mk 13:22; II Th 2:9; Rev 13:1-15).  Wonderful works to not prove that one is of God (see Deuteronomy 13:1-3 and Matthew 7:21-23).  Satan can appear as an "angel of light" (II Corinthians 11:14-15).  Again, beware:  don't allow him to lead you astray from God's "only" authority, the written Word of God.

In a future section, we will be looking at "speaking in tongues", and showing that even if this gift were for today it would follow the Biblical guidelines clearly defined in Scripture (I Corinthians 14).  However, again the authority of the charismatic movement in this area is experience rather than the Word of God.

Salvation
Though charismatics believe in the necessity of the new birth (John 3:3), they are confused about the Saviour's power to keep those that He saves, and they are confused about the need for one to "trust" only the Saviour for Biblical salvation.

Charismatics teach that Christians can lose their salvation because of sin.  They find it hard to define which sins or how much sin causes one to lose his salvation, but they believe that Christians fall in and out of salvation based upon their behaviour.  The problem is:  if one's sin causes one to lose his salvation, which is attained solely because of the grace of God through faith (Romans 3:24; Galatians 3:26), how does one get his salvation back?  What this basically teaches is that one's behaviour must be changed or improved to get salvation back once it is lost, and this is salvation by "works", which is very dangerous teaching and contrary to Scripture (Ephesians 2:8-9).  The Bible clearly teaches that Christians are secure in their salvation in Jesus Christ, not because of their behaviour but because of the person of Jesus (see the pamphlet on eternal security for more information).  Ultimately they believe in a different Jesus  One who cannot keep them (I Peter 1:5), preserve them (Jude 1:1), protect them (John 10:28-29), or seal them "until the day of redemption" (Ephesians 4:30).
This dangerous teaching on salvation is often used as a control tool to try and keep Christians "in line".  However, this teaching eventually has the opposite effect because Christians realize that they cannot keep their salvation (which we can't, only He can!), and they often give up.  Whether or not we feel saved does not define whether or not we are saved.  Salvation is based upon the Word of God, not our feelings.

Another confusion is the nature of man's part in salvation.  Man must not only repent (Luke 24:47), but he must "trust" Jesus Christ as his only hope for heaven (see Ephesians 1:12-14).  Many charismatics believe that they are saved because they got caught up in the emotion of a church service or a plea for salvation and they had an emotional experience or spoke in tongues.  They therefore assume that they must have been saved because of the emotion or experience.  Emotions and experiences do not save.  Prayer does not save.  Only Jesus saves!  Many went forward at a meeting and were "prayed over" by the speaker who then told them that they were saved.  Being "prayed over" is not salvation - a speaker cannot save another person.  One must clearly understand the gospel (sin and it's penalty, who Jesus is and what He did) and personally place his trust and faith in Jesus Christ for salvation.

Speaking in Tongues
One of the earmarks of this movement is "speaking in tongues".  The word "Pentecostal" is derived from "Pentecost", the name of the day when the first incidence of "speaking in tongues" occurred.  The word "Charismatic" is derived from the Greek word for gifts, which is "charisma".  As implied by these names, the miraculous gifts are important to this movement.  The gift of "speaking in tongues" is considered the most important by this movement, and people in the movement are taught that each Christian is to exercise this gift.

The word "tongue" in the Bible always refers to "a language".  The Greek word for tongue is always the same, "glossa".  Some good examples are found in Acts 2:11 and Revelation 5:9; 7:9; 10:11; 11:9; 13:7; 14:6; 17:15.  In Revelation 9:11, the phrases "Hebrew tongue" and "Greek tongue" make it clear what the word means.

God worked a miracle in the lives of the early disciples and gave them the ability to preach the gospel in a language that they had not learned.  In Acts chapter two, many Jews from sixteen other areas of the world heard the gospel in their own language and were saved.  This was the beginning of the great church in Jerusalem.  This miraculous gift was given for two very important reasons:  1) to break language barriers so many could be saved in the early days of the church and, 2) as a temporary sign to the Jews (see I Corinthians 1:22; 14:21-22) that the message of these disciples was from God, since the New Testament was not written yet (see Hebrews 2:2-4 and Mark 16:20, especially the phrase "was confirmed" in Hebrews 2:3).  "Speaking in tongues" was another of the "signs of an apostle" (see II Corinthians 12:12), which are not mentioned from II Corinthians to Revelation. 

Remember, this was a "gift" from God.  It did not have to be taught or learned, even though many churches today "teach" people how to speak in tongues.  Another important consideration is this:  If the Biblical "gift" of tongues is present today, why do fervent, spiritual missionaries (even Pentecostal/charismatic ones) have to spend years learning new languages so they can preach the gospel?

It is taught by this movement that speaking in tongues is the evidence of the filling of the Holy Ghost.  However, Jesus prophesied of the filling of the Holy Ghost and did not mention speaking in tongues (Luke 24:49).  Acts 1:8 makes it clear that the filling was for the preaching of the gospel.  Many times in the book of Acts, people were filled but they did not speak in tongues (see Acts 4:8, 31; 9:17-18; 13:9, 52).  Of the seventeen times in Acts where people were saved, in only three of them was tongues involved.  I Corinthians 12:28-31 makes it clear that not every Christian would be given this gift, which is listed as the "least" of the gifts.

One church in the Bible (Corinthians) was overly magnifying this gift and abusing it.  This church was very carnal, so the book of I Corinthians was written as a rebuke (see II Corinthians 7:8-9) to correct them.  In chapter fourteen, God gave some Biblical guidelines for speaking in tongues.  These guidelines were given to make sure that everything was done decently and in order.  For those who believe that the gift of speaking in tongues is still available to Christians today, these guidelines would be followed by the Holy Ghost, since He wrote them.  Any church that encourages the speaking in tongues should ensure that these guidelines are being followed.  Otherwise, maybe the Holy Ghost isn't the One motivating the tongues (see Deuteronomy 13:1-5; II Thessalonians 2:9-10; Matthew 24:24 which show that Satan can also work through the miraculous).  These guidelines are as follows:

1. I Cor 14:21-23, a sign for Jewish unbelievers' benefit only (see I Cor 1:22)
2. I Cor 14:12, 26, for edification of others
3. I Cor 14:27, only two or three in a given church service
4. I Cor 14:27 (also vs. 23, "all"), must take turns
5. I Cor 14:28, must always have an interpreter present or keep silent
6. I Cor 14:33, 40, no confusion; decently and in order
7. I Cor 14:34-35, women not to participate in speaking in tongues in the churches

If you were to check, you would find that churches which have "speaking in tongues" today do not follow most of these Biblical guidelines.  There must be a serious problem.  If the current practice breaks these guidelines, then it cannot be from God, for He never violates His own Word.  If the gift of "speaking in tongues" is available today, so must the gift of "interpretation of tongues" be available.  What occurs, however, is multiple interpretations of the same unknown phrase, which would be impossible with God involved.

The Bible even warns against the common practice of "praying in tongues" because the understanding is not there (see I Corinthians 14:14-15).  We must agree with Paul when he said, "in the church I had rather speak five words with my understanding, that by my voice I might teach others also, than ten thousand words in an unknown tongue", I Corinthians 14:19.  This "speaking in tongues" movement is being used by Satan to unite non-Biblical churches, even churches that do not preach the gospel.  Beware!

Healing and Miracles
We serve a miracle-working God (see Matthew 19:26)!  He answers prayer and heals when it is His will (see James 5:16).  However, the charismatic movement teaches that Christians today still posses the "gifts of healing" and the "working of miracles", as listed in I Corinthians 12:9-28.  As explained in "Speaking in Tongues", God gave temporary sign gifts to prove to the Jews (see I Corinthians 1:22; 14:21-22) that the message of the disciples was from God, since the New Testament was not written yet (see Hebrews 2:2-4 and Mark 16:20, especially the phrase "was confirmed" in Hebrews 2:3).  These gifts were part of the "signs of an apostle" (see II Corinthians 12:12).

This understanding can be tested by looking at the New Testament occurrences of these gifts.  When these gifts were exercised, they were unmistakable, and "faith" in the one being healed was not a factor (see Acts 3:1-8; 5:12-16; 9:40; 19:11-12; 20:9-12; and see "every one" and "all" in Matt 4:23-24; 8:16; 9:35; 12:15; 15:30; 19:2; Lk 4:40; 6:17-19; and Acts 5:16).  Every one was healed completely, even those lame from birth.  People were raised from the dead (see Acts 9:40 and Acts 20:9-12).  Some were healed simply by touching a handkerchief which had been touched by Paul (see Acts 19:11-12).  The supposed gifts of healing and miracles performed today do not even compare to the ones performed by the men in the New Testament with those gifts.  In addition, the apostles did not accept payment in any form (see Acts 3:6).
If one researches it, they will find that John the Baptist "did no miracles" (see John 10:41), and that the only ones in the New Testament who exercised these miraculous gifts were Jesus, the twelve disciples, and four others:  Stephen, Philip, Paul, Barnabas. Each of these other four had hands laid on them by the apostles in Acts 6:6 and Acts 13:3.  Again, that is because these gifts were passed on by Jesus for a temporary sign to the Jews.  As a matter of fact, these apostolic gifts began to fade even before Paul died (see I Tim 5:23; II Tim 4:20).
Another wrong teaching stemming from these errors is that it is God's will for everyone to be healthy.  However, sometimes it is God's will for His children to suffer (see Job 2:1-7; Rom 5:3; II Cor 11:30; 12:7-10; I Pe 1:6-7; 4:12-13; 5:10).

Remember, God still heals and works miracles in answer to the prayers of God's people and when it is His will.  However, no Christian today possesses these apostolic gifts.  If they did, they would empty the hospitals!

Prosperity Theology A prominent teaching of the charismatic movement is that Christians close to God are always physically blessed of God.  I say "physically" because God always blesses His faithful servants with peace, joy, contentment, gratitude, etc.  However, the charismatic movement teaches that one's spirituality can be measured by his outward, physical circumstances.  In other words, if one is healthy and/or physically prosperous, God is with him and vice versa. 
Job's friends also believed this wrong teaching.  They were convinced that Job was suffering because of sin and that God would not bless him again until he repented of that sin.  However, they were wrong.  Job was right with God and still he suffered physically - probably more than any person in history other than Jesus Christ.  At the end of the book of Job, God rebuked Job's friends for their wrong theology, "prosperity theology".
People can still fall into this same trap today!  If they are not careful, they will determine their closeness to God based upon their circumstances.  Of course God often will use suffering as a form of chastisement (see II Samuel 12:14; Psalms 119:67, 71; I Corinthians 11:30-32; Hebrews 12:6-11).  He also teaches us that we "reap what we sow", Proverbs 1:31; Galatians 6:7-8.  For example, if you smoke, you might get lung cancer, etc. 
However, not all suffering is God's chastisement.  Some suffering is just the result of the curse.  Things like arthritis, brittle bones, memory loss are just part of getting older (see Romans 8:22-23).  The Bible also teaches that Christians who live "godly" are going to suffer persecution (see I Peter 4:12-16; II Timothy 3:12).  The Christians of Hebrews 11:32-29 who were tortured, scourged, imprisoned, stoned, and sawn asunder are listed as people of great faith, not people who suffered because of sin.  "Foxes Book of Martyrs" lists hundreds of faithful Christians of the past who suffered pain and death for doing "right".

Beyond these things, God often uses suffering for our good.  He knows that testing strengthens our faith and refines us (see I Peter 1:6-7).  II Corinthians 4:16-17 says that "affliction" is good for us.  I Peter 5:10 says that suffering will "perfect, stablish, strengthen, settle" us.  Romans 5:3 says that tribulation works patience.

One's closeness to God is often independent of the pleasantness of his external circumstances.  Be careful not to be fooled by this wrong system of belief called "prosperity theology".