One of the devil's oldest tricks is to try to convince us that God doesn't really love us, and that even if we have given our lives to Christ, God may change His mind and abandon us. In other words, Satan wants to rob us of our assurance and make us doubt our salvation.
But it isn't true! If you sincerely asked Jesus to come into your life and save you, then He did–and nothing can ever change that. Jesus said, "Whoever comes to me I will never drive away" (John 6:37). He also promised, "Whoever lives and believes in me will never die" (John 11:26). Put your trust in what God has told us in His Word, not in Satan's lies.
When you gave your life to Christ and trusted Him for your salvation, He adopted you into His family. Think of it: You are now His child forever! If you sin (and you will), your fellowship with God may be broken–but your relationship is unchanged, and you are still His child. The Bible says, "This is the testimony: God has given us eternal life, and this life is in his Son. He who has the Son has life" (1 John 5:11-12).
Never forget: Your salvation does not depend on you; it depends solely on Christ and what He did for you through His death and resurrection. Make it your goal to grow closer to Him through reading the Bible and prayer and fellowship with other believers. The closer we get to Christ, the stronger our faith becomes.