In the years following the life, death and Resurrection of Christ, many argued over the identity of this mysterious man named Jesus. Even many Christians began to doubt the divinity of Christ, putting into question God's love and grace. John wrote these letters to present a clear picture of the Lord and Savior Jesus Christ to assure believers in their faith.
1 John 5:13 -- "I have written this to you who believe in the name of the Son of God, so that you may know you have eternal life."
1 John 1:7 -- "But if we are living in the light, as God is in the light, then we have fellowship with each other, and the blood of Jesus, his Son, cleanses us from all sin."
By knowing and walking in His love, we have the ability to confidently walk through our life knowing that God gives us eternal life with Him. We can come to know peace and joy even in this fallen world and share that love with others.
2 John 1:6 -- "Love means doing what God has commanded us, and he has commanded us to love one another, just as you heard from the beginning."
How we treat others reflects our true values. We have to evaluate ourselves and determine whether we will live and love as Christ did or conform to the selfishness of the world.
Jesus Christ lived a life of truth and love and sacrificed himself to save us. He is the light of the world and provides us life. It is our choice what to do with our life, but God wants us to live for Him. Not conforming to the world is hard, but God gives us rewards for our faith and a life full of purpose and love. John knew that love, since he spent his whole life in God's presence. He wants us to know that is not only possible to walk with and fellowship intimately with Christ, but that it is worth it.