1. The bad news:
Since Adam and Eve, every person has sinned against God. Sin is doing something that God does not want you to do, or not doing something that God wants you to do. The bible tells us that the payment due for sin is death (Romans 3:23). Because of sin, we cannot have a relationship with God (Psalm 24: 3-4). Our sins have made our hands and hearts impure. We can do nothing to cleanse ourselves from sin.
2. The Good News:
God solved our sin problem. He sent His Son Jesus - God in human flesh - to earth. He came to die for us. His death was a sacrifice to pay for our sins.
God offers us forgiveness, a relationship with Himself, and victory over sin in our lives. Forgiveness and a relationship with God - Salvation - cannot be earned or deserved. It is a gift from God.
3. How to respond to Gods offer:
Believe that Jesus death purchased forgiveness for you. Trust in Him to make you right with God as His child. Admit (confess) to Him that you have sinned. Ask Him to come to live in you and forgive your sin.
4. The guarantee:
Jesus promises that at the point when you put your faith (belief) and trust in Him as your Savior - He gives you eternal life. Eternal means that it will never end and never be taken away. You cannot loose your salvation once you have it. You never need to be saved again. You did not do anything to merit your salvation, and you cannot do anything to loose it. God saved you and you belong to Him. He will never leave you or forsake you (John 5:24, John 6:47, I John 5:10-12).