Christ has already given his life for us; what more can He do? So much more! Reasoning from the lesser to the greater: If while we were enemies, Christ reconciled us to God; how much more, now that we’re reconciled, will God save us! And if the death of Christ brought us reconciliation, how much more will the life of Christ save us!
“For if while we were enemies we were reconciled to God by the death of His Son, much more, now that we are reconciled, shall we be saved by His life.” (Romans 5:10 ESV)