In John 3:16 he wrote "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life."

His son was Jesus who came down and became a man to save us from our failings.

Paul wrote in Romans 5:8 "But God demonstrates his own love for us in this: While we were still sinners, Christ died for us."

In order for us to be rescued from the punishment of our sins, Someone had to stand in our place and take that punishment on themselves.