"Not everyone who says to Me, "Lord, Lord," will enter the kingdom of heaven, but he who does the will of My Father who is in heaven will enter" (Matthew 7:21).
Here Jesus is speaking of the devotedly religious who think they are saved but aren't. The Lord will continue these warnings later about spiritual self-deception - the foolish, unprepared virgins (Matthew 25:1-12) and the goats who did not really serve Him (Matthew 25:32-33, 41-46).
Many factors deceive people regarding salvation. First, some have a false assurance. They rely on past "decisions for Christ," apart from the Spirit's convicting work. But our salvation is made secure by increasing evidences of fruitfulness (2 Peter 1:3-11).
Second, many fail to examine themselves (2 Corinthians 13:5; 1 John 1:8-9), instead gliding through life unconcerned about sins. One who has no desire to come to God for continued cleansing is likely not saved.
Third, a person can be deceived even in the midst of much religious activity. Hearing sermons, reading the Bible, and attending Bible studies are good, but such things may insulate someone from true worship.
Fourth, many attempt to rationalize their salvation, thinking that their good deeds outweigh their bad ones. But apart from God, we cannot do anything righteous (Psalm 14:1-3; 5:1-3; Romans 3:12).
We could mention many other spiritual delusions, all of which involve failure to enter the narrow gate with repentance, submission to Christ, humility, and a desire for holiness. The important thing, however, is not to wonder about all those possibilities but to enter God's one true way to salvation.
Is the validity of your salvation ever in doubt in your mind? Do you see yourself in any of the examples given above? Then anchor your faith today in the sure word and promises of God, and walk in the confidence of eternal life, bought and paid for by Jesus Christ.