1. When someone says there is another way to God other than through Jesus. Acts 16:17 (The woman possessed with a spirit of divination literally declared that Paul was showing "a way" (Greek) to God, implying there were other ways.) Many people believe that there "many" ways to God such as living a good life, praying to some saint, belonging to some particular church, or becoming a martyr for their religion.
2. When tradition takes precedence over hearing and obeying the Spirit of God. Colossians 2:8-17. (The feasts and sacrifices are mentioned here). Mark 7:9-13 (Jesus said that the Pharisees made void the commandment of God through their traditions.) Traditions often bring a dullness to hearing the voice of the Holy Spirit. Denominationalism is often takes precedence over the moving of the Holy Spirit.
3. When one uses religion to "control" others. I Kings 13:18 (The old prophet lied to the young man of God saying that he had heard from God that the young prophet was to stay and eat.) Personal prophecies should be examined and validated and not accepted just because someone gave them.
4. When the means of worship becomes the object of worship. Numbers 21:9, II Kings 18:4 (The people began to worship the brazen serpent on the pole which had been used as a means of worship earlier.) Our churches are often guilty of worshipping the form of worship (three hymns, offering, prayer, and a three point sermon).
5. When one excuses his sin as a act of worship. I Samuel 15:15, 23. (Saul said that he had taken the forbidden spoil to sacrifice unto the LORD.) I Samuel 2:22 (The sons of Eli had sexual relations with the women who came to worship). It would be like the pastor who says to a woman who comes for counsel, "If you want a real spiritual experience, you will have sex with me."
6. When one incorporates pagan worship into true worship. Exodus 32:5 (After Aaron carved a mold, made the molten calf, and made an alter for it, then he demanded that the people have a feast unto the LORD.) The gold calf was a type of Baal worship. Many churches today incorporate humanism along with Christianity into their church.
7. When one seeks revelation outside of God and His Word. I Samuel 28:7 (Saul consulted the witch of Endor). People often go from church to church to get a personal word from God from various prophets. This is not to say that God does not on occasion speak to individuals, but people may come to depend upon the prophecy rather than God and His Word and become subject to false prophecies.
8. When one demands worship of himself. Daniel 3:1-6 (Nebuchadnezzar had an image of himself built and demanded that everyone worship it) (Of course it can also be a false image of one's self, being greater than them are). John 9:34 (After Jesus healed the blind man some of the Pharisees questioned him and belittled him by saying, "Thou wast altogether born in sins, and dost thou teach us?" And they cast him out.) Sometimes even ministers or priests demand worship.
9. When one looked for signs and wonders being the primary source of truth. (Superstition) Exodus 32:24 (Aaron implied that the gold miraculously came out of the fire as a calf.) Revelation 13:13-15 (During the tribulation period, the Satan will use miracles to deceive many people). Sometimes people think that the church that has the most signs and wonders is the most spiritual.
10. When one tries to gain or maintain his salvation through doing good works rather than relying upon the grace of God found in Jesus. Matthew 19:16-21 (The rich young ruler had kept the commandments from his youth, but that was not enough). False religions and even churches today often teach that one has to do such and such to be saved or to maintain their salvation. Hebrews 6:1, 9:14 (Both Scriptures declare that such are dead works).
11. When one has a mystical belief about God, but has not submitted himself to Jesus as his Lord. Acts 19:14 (The seven sons of Sceva tried to cast out a spirit by the Name of Jesus, but got cast out naked themselves . The evil spirit said, "Jesus, I know, and Paul I know, but who are you?") Neither knowledge or rituals make one a true Believer.
One can't enter into spiritual warfare without knowing who the enemy is!