This is one of the most important questions in the Christian life. Many believers doubt their salvation because they don’t see signs of genuine faith in their lives. There are those who say we should never doubt our decision to follow Christ, but the Bible encourages us to examine ourselves to see if we are truly “in the faith” (2 Corinthians 13:5). Thankfully, God has given us ample instruction for how we can know for sure that we have eternal life. The first epistle of John was actually written for that purpose, as it states in 1 John 5:13, "I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life."