Read 1 Kings 13.
“Because you have disobeyed the word of the LORD and have not kept the command that the LORD your God commanded you, but have come back and have eaten bread and drunk water in the place of which he said to you, “Eat no bread and drink no water,” your body shall not come to the tomb of your fathers.” (verses 21-22)
Disobedience to God is always extremely costly – even if you are deceived into disobeying. That’s what the anonymous “man of God from Judah” found out when he took the old prophet from Bethel up on his invitation to dinner. The man of God from Judah had a specific command from the Lord not to eat or drink. He did not get a pass on his disobedience just because the old prophet lied to him. In this case, God’s judgement was swift and sure (1 Kings 13:24). Really, all disobedience to God comes as a result of deception. Eve was similarly deceived into disobedience (Genesis 3), and Jesus has warned us that Satan is a deceiver (John 8:44). Deception is no excuse for disobedience, regardless of how overt or subtle the deception. We are to expect deception (Matthew 7:15) and be armed against it with the truth of God’s Word (John 17:17; Ephesians 6:17; 1 Peter 5:8-9).
You do not want to be deceived by someone who claims that God has given him a new revelation or a new interpretation of Scripture that He has not given you. This is how every cult and every fake version of Christianity starts. God does not contradict Himself. He will never tell you to do something that He has already told you not to do. Don’t be deceived into believing otherwise. Test everything you hear against Scripture (Acts 17:10-11; 1 John 4:1).