The necessity of belief for salvation is repeated several times in John 3. For anyone to be saved from sin, he or she must believe, or trust, in who Jesus is and that He has done everything necessary for salvation from sin. If we place our faith in Jesus Christ, He will give us eternal life. But that is not where the blessings end.
Trusting in the finished work of Christ also means living from the victory He won on the cross. After we’ve placed our faith in Jesus, our salvation can never be taken away from us (Rom. 8:38-39). Neither persecution, death, nor even our own sin can separate us from the love of God. We can trust this to be true, even in the face of doubt, because even though it is through our faith that Jesus saves us, it is not our faith in Jesus that sustains our salvation. What sustains our salvation is the completed work of Jesus—His life, death, burial, and resurrection—and the unending power of God to preserve our salvation no matter what.
What doubts do you face in your walk with Christ? How does His completed work on the cross help you continue to believe?