The confidence you have in a promise is dependent on the one who guarantees the promise. The assurance of the gospel is singularly founded on the personhood of Jesus. Being the incarnate eternal God through whom all things were created and in whom the eternal redemptive plan of God is fulfilled. Jesus is not limited by the fragility of man—He has always been, He is, and He will always be. The hope of the gospel rests on God alone. And this is the hopeful word of verse 5: even though the world opposes the light, it will not overcome the light. Like the sunrise that dispels the grip that darkness has on the world and demands that it surrender in defeat, so is the glory of the light of the gospel. Darkness is presently warring against the light, but it will not overcome it.