As I sat on a train headed for an important appointment, I began to wonder if I was on the right train. I had never traveled that route before and had failed to ask for help. Finally, overcome by uncertainty and doubt, I exited at the next station—only to be told I had indeed been on the right train!

That incident reminded me how doubt can rob us of peace and confidence. At one time I had struggled with the assurance of my salvation, but God helped me deal with my doubt. Later, after sharing the story of my conversion and my assurance that I was going to heaven, someone asked, “How can you be sure you are saved and going to heaven?” I confidently but humbly pointed to the verse that God had used to help me: “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” (1 John 5:13).

God promises that through faith in His Son, Jesus, we already have eternal life: “God has given us eternal life, and this life is in his Son” (v. 11). This assurance sharpens our faith, lifts us up when we are downhearted, and gives us courage in times of doubt.