II. HOW TO DISCERN A FALSE PROPHET OR TEACHER
A. Christians are exhorted to test the spirits or to discern the spirit that is behind a teaching ministry. 1Beloved, do not believe every spirit, but test the spirits, whether they are of God; because
many false prophets have gone out into the world. (1 Jn. 4:1)

B. We are called to test all doctrines and ministries that we are open to receive from. We must challenge each teaching that we hear in the light of Scripture.
21Test all things; hold fast what is good. (1 Thes. 5:21)

C. We can avoid deception by growing in our relationship to Jesus by holding fast to Him. Practical ways to hold fast to the head include regular, prayerful Bible reading, setting our hearts to obey the Lord, and staying in relationship with others, while maintaining a teachable spirit.
19Holding fast to the Head, from whom all the body…grows with the increase… (Col. 2:19)

D. A cult is a group that refuses historic Christianity and has an unusual devotion to one leader whose set of beliefs are not found in Scripture (as affirmed in historic Christianity). Members of a cult see themselves as the only ones who possess the complete truth; they see the larger Body of Christ as being apostate.

E. We must both warn and rescue those who are involved in false teaching and practice. It is easier to prevent someone from joining a cult than it is to get them out afterwards. Part of the
forerunner ministry is to warn and rescue loved ones involved in cults by teaching them the truth.

F. The conflict in the end times will be the battle for truth. Satan’s weapon will be deception; our defense will be love for the truth. This battle will focus on defining who Jesus is and how we are to love Him. We must love God on His terms. Our love for God must be expressed through allegiance to Jesus and the Bible. The Spirit exalts Jesus by guiding us into all truth about Him.Truths about Jesus that offend humanists include His right, as God, to establish absolute standards to which the nations will be held accountable; second, that Jesus is the only way of salvation; and third, that Jesus possesses the wisdom and love to judge sin in time and eternity.

G. We must accept the main historical Christian doctrines, which include:
Jesus, God’s only son, is fully God and fully man, born of virgin birth, without sin
Jesus’ death and bodily resurrection and ascension to the Father’s right hand
The one true God exists in three persons (the Trinity) as Father, Son, and Holy Spirit
Salvation is by faith alone, through grace alone, and in Christ alone
The infallibility of Scripture as our final authority for all matters of faith and practice
The unity and diversity of the Body of Christ

H. Historic orthodox Christianity is defined in statements such as the Apostles’ Creed, the Nicene Creed and the Westminster Confession

Source: http://www.mikebickle.org.edgesuite.net/MikeBickleVOD/2009/20090828_How_to_Discern_False_Teachers_and_Cults_UMC05.pdf