Dear Vic, Let's start with salvation itself. The Bible says that there is nothing that we can do to earn our salvation.
Salvation is by and through grace.
His lavish gift of eternal life is not something we can ever earn, by any work of merit. God can never be obligated to us. Salvation is eternal life, given to us when we are saved. Those who are eternally saved cannot earn that eternal life. Neither can they do anything to make sure that is maintained.