You don't "maintain" grace, grace keeps us. You either accept or reject it - it is the gift of God, not of works lest any man should boast. We are "his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them." (Ephesians 2:10) Our works are NOT and CAN NOT save us. Those who have been born again by faith in Christ are new creations and are indwelt by the Holy Spirit of promise. It is that spirit at work in us conforming us into the image of Christ. That is why genuine faith WILL result in a changed life that seeks to love and honor the Lord because HE first loved us. It is wrong, however, to imagine that it is our works that merit, earn or cause us to deserve salvation. It is ALL by grace - from start to finish:
For the gospel reveals the righteousness of God that comes by faith from start to finish, just as it is written: - The righteous will live by faith. (Romans 1:17)