Sadly, some go through life wondering how to tell if they are saved. They live each day in anxiety about their soul's eternal destiny. However, there is something worse; those who are wrongfully convinced they are saved. People in either of these conditions will not be saved. Those who erroneously believe they are saved, of course, will not go to heaven. Those who are not sure will not go either. No one who makes it to heaven will be surprised to be there because it requires a concerted, determined effort (Col. 3:1, 2; Heb. 11:6). So, how do you know, correctly, you are saved?
You do not know you are saved simply because you are sincere. The prophets of Baal were sincere, but they were sincerely lost (1 Kings 18:25-29). They truly believed Baal was real, even to the point that they cut themselves. Yet, all the sincerity in the world did not make it a reality.
You do not know you are saved, by feeling it. Saul felt compelled to offer a sacrifice (1 Samuel. 13:8-14). However, Saul was misled by his feelings and stood condemned. Jacob felt Joseph was dead. There was even "evidence" to lead him to that feeling (Genesis 37:29-36). His feelings were wrong; Joseph was alive.
You do not know you are saved because you are religious. The Pharisees and Sadducees were religious men, but they were hypocrites (Matthew. 6:1-18). Saul of Tarsus was religious too and he was not a hypocrite, but was nonetheless lost (Philippians 3:4-6; Acts 23:1). Regular worship, study, and prayer did not mean these men were saved.
You do not know you are saved because you are moral. Cornelius was a moral man (Acts 10:1, 2). He treated his fellowman with kindness and love. He was not only moral, but devout too. Still, the angel told him he must be saved (Acts 11:14).
So, how do you know if you are saved? You know when the Word of God tells you you are saved. In other words, if you do what the Bible tells you to do, then you will know you are saved. Have you believed in Jesus (John. 8:24)? Have you repented of your sins (Luke. 13:3)? Have you confessed Christ before men (Luke. 12:8, 9)? Have you been baptized to have your sins washed away (Acts 22:16)? Remember, the Holy Spirit promised that those who repent and are baptized will receive the remission of sins (Acts 2:38). This, of course, was based on belief in Jesus (Acts 2:36, 37).
What about the Christian? How can a Christian know he is saved? We can know in the same way as stated above, by the Word of God. Paul said, "The Spirit Himself bears witness with our spirit that we are children of God, and if children, then heirs, heirs of God and joint heirs with Christ, if indeed we suffer with Him, that we may also be glorified together" (Romans 8:16, 17). When our spirit adheres to what the Holy Spirit revealed in the Bible, then we are truly children of God and will inherit salvation. Generally speaking, we are saved and will be saved if we "do not walk according to the flesh, but according to the Spirit" (Romans 8:1).
Thankfully, we are not left to guess about salvation. God has revealed what man must do to be saved and stay saved. How do I know I am saved, by God's eternal, sure, steadfast Word!