You are saved by grace through faith, and you stay saved by grace through faith, not through the Law. You don't start a spiritual journey with God based on the free gift of righteousness, then keep it by your works.
Yes, your salvation will produce good works, but the presence of those works is not the security of your salvation, Jesus is. Jesus is your once and forever sacrifice and scapegoat for your sin, as well as the one that holds your place in the everlasting covenant secure. Rest in him.