“But the Spirit explicitly says that in later times some will fall away from the faith, paying attention to deceitful spirits and doctrines of demons,” 1 Timothy 4:1

We are warned several places in scripture to watch out for those who will deceive us. They may even come lending a hand, “they came to Zerubbabel and the heads of the fathers’ houses, and said to them, “Let us build with you, for we seek your God as you do; and we have sacrificed to Him since the days of Esarhaddon king of Assyria, who brought us here.” Ezra 4:2

We see that men came to Zerubbabel declaring they were following the same God as they were. How did Zerubbabel know that these were deceivers and how will we know?

The only way to know if you are being deceived is to know the truth, “Sanctify them by Your truth. Your word is truth.” John 17:17.

We must be one with God so we can be divinely warned. “By faith Noah, being divinely warned of things not yet seen, moved with godly fear, prepared” Hebrews 11:6

Thankfully, there is no dispute about what is truth, “Forever, O Lord, Your word is settled in heaven.” Psalm 119:89