Therefore we must know the word of God to discern truth from fiction because deception is lurking around every corner. Satan comes but to steal, kill and destroy, prowling like a lion looking for someone foolish and weak to devour. He also comes masquerading as an angel of light who will deceive even the elect if it were possible. Satan's powers of deception are strong, added to which, God Himself will send powerful delusions upon those who wilfully reject His truth and chose paths of unrighteousness:
"And then the lawless one will be revealed, whom the Lord will consume with the breathe of His mouth and destroy with the brightness of His coming. The coming of the lawless one is according to the working of Satan, with all power, signs and lying wonders, and with all unrighteous deception among those who perish because they did not receive the love of the truth, that they might be saved. And for this reason God will send them strong delusions, that they should believe the lie, that they all may be condemned who did not believe the truth but had pleasure in unrighteousness." - 2 Thess 2:8-12.
God will send delusions upon those (who name themselves Christians) who chose to believe and follow lies. This is a core danger of believing the 'once-saved-always-saved' doctrine, a doctrine that can lead people into a false sense of security by which they drift into sinful ways believing they are 'saved'.
"Blessed are those who do His commandments, that they may have the right to the tree of life and may enter through the gates into the city. But outside are dogs (symbolic of unclean people) and sorcerers and sexually immoral (by God's standard) and whoever loves and practices a lie" - Revelation 22:14-15.
Don't be fooled by false doctrine or politically correct practice and tradition in church, however 'right and just' these things may sound - test everything. Ask God to show you by asking the Spirit of Truth to lead you into all understanding. Be wise and be blessed...!