"It" is the means of salvation for us. Jesus means Jehovah is Salvation. Christ means Anointed Jesus kept the promises made by his Father, providing the means of salvation for all humans who want it, and show it by faith in him.
For God did not send his Son into the world for him to judge the world, but for the world to be saved through him.
2 Corinthians 1:20
For no matter how many the promises of God are, they have become “yes” by means of him. Therefore, also through him is the “Amen” said to God, which brings him glory through us.