As Christians, what assurances do we have that we will be with God after we die? What assurances do we have that we will live forever in heaven? The author of the biblical book of 1st John wrote to Christians to encourage them in their faith. In the face of false teachers and heresies, he provided tests for them so that they could be assured of their future. “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” (1st John 5:13).  

There are three basic tests of an authentic believer. The first test regards our understanding of Jesus.  Do you currently believe that Jesus is the Son of God, the Christ? “No one who denies the Son has the Father; whoever acknowledges the Son has the Father also” (2:23).  To acknowledge the Son in the context of the letter means to believe that he was fully human and to simultaneously believe that he was fully God.  To deny the Son is to have a wrong understanding of his revealed identity. Lots of people say they “believe” in Jesus, but do you believe in the Jesus revealed in the Bible?  

The object of our faith matters. What good is trusting in a Jesus who never existed? We need to place ourselves under the Jesus of history, the Jesus of the Bible. Do you believe that he was eternal God who, without ceasing to be God, took on a human nature? “Who is he who overcomes the world? Only he who believes that Jesus is the Son of God” (5:5).   

The second test regards our behavior.  Are we actively seeking to obey the commands of Christ? “We know that we have come to know him if we obey his commands” (2:3). “The world and its desires pass away, but the man who does the will of God lives forever” (2:17). “The man who says, ‘I know him,’ but does not do what he commands is a liar” (2:4). In keeping with the emphasis on keeping the commands of God is the necessity of leaving a life of sin. “If we claim to have fellowship with him yet walk in darkness we lie and do not live by the truth” (1:6). “No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him” (3:6).  

What John is not saying is that Christians will be sinless or that human perfection is a requirement for salvation (see 1:8-9). What John is saying is that authentic Christians will not be content remaining in a sinful lifestyle; those who have eternal life will seek to move out of the darkness, they will seek to please God. “No one who is born of God will continue to sin, because God’s seed remains in him; he cannot go on sinning, because he has been born of God” (3:9). A desire to follow God is a consequence of being spiritually renewed. Are you seeking to follow Jesus? Good! Are you seeking to be like him in his holiness? Praise God! “Whoever claims to live in him must walk as Jesus did” (2:6).   

There is a third test which is connected with the first two, but it focuses on how we treat people.  “Anyone who does not do what is right is not a child of God; nor is anyone who does not love his brother” (3:10).  Do we love others?  “This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers” (1 John 3:16).

Jesus Christ gave himself up for us, so a mark of our having a saving and real relationship with him is seen in our giving ourselves up for the benefit of others in the church. “Anyone who claims to be in the light but hates his brother is still in the darkness. Whoever loves his brother lives in the light…”(2:9). “Whoever does not love does not know God, because God is love” (4:8).  

Have you been saved? Will you be with God in heaven when you die? “To profess knowledge of God without a holy life, without a clean break from sin and a deep love for other Christians, is as much a delusion as to deny the incarnation of our Lord Jesus Christ. Belief and behavior are inseparable” (David Jackman).