Romans 16:17 I urge you, brothers, to watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them. 18 For such persons do not serve our Lord Christ, but their own appetites, and by smooth talk and flattery they deceive the hearts of the naive.
Christians who do not know the Bible can be deceived by people who misuse the Bible to gain a following. The cults, like the Jehovah Witnesses and Mormons do this. In the time of Paul, the people who were Gnostics and Judaizers were people who misused the Bible to gain their own following.
What will keep you from being deceived and divided as a local church? You need to learn the Bible. You need to be in a Bible based local church that has elders to guard the flock (Read Acts 20:17-35 which is Paul instructing the elders of the local church of Ephesus how to guard the believers from false teachers).
Are you diligently learning the Word of God? Take some time each day to systematically study the Bible. A good way to begin a systematic study of the Bible is to begin by reading Genesis chapters one through eleven. Continue by reading Matthew through Revelation.
Are you in a local church that has elders to guard the flock from false teachers who bring division? How do you find a local church that has elders who guard the flock from false teachers? Call up local churches and ask to speak with one of the elders. Ask the elders how a person is saved and see if it fits with Ephesians 2:8-9. Ask the elder how a person lives according to the Bible and see if the answer fits Galatians 2:20 and 2 Corinthians 12:9. Ask the elder to direct you to a passage of scripture that describes the qualifications of an elder and see if he leads you to 1 Timothy 3:1-7; Titus 1:5-9 and Acts 20:17-35.
Do begin to diligently study the Bible systematically and be involved in a local church that is guarded by elders who fit the qualifications of 1 Timothy 3:1-7; Titus 1:5-9; and Acts 20:17-35.