2nd Timothy 2:19 says, "Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are his." It is not good enough for you or I to say we know the Lord Jesus. But when we can have the blessed assurance that the Lord Jesus knows us, that is "unmerited favor!" The verse goes on to say. "And, Let every one that nameth the name of Christ depart from iniquity." There can be no question that this means that our post conversion lives should reflect a different lifestyle.
The Apostle Paul had some interesting things to say about the grace of God in Titus 2:1-15. I won't take time to put it all here. You can turn there in your own Bibles and read it for yourself. But in Titus 2:11-12 the Bible says, "For the grace of God that bringeth salvation hath appeared to all men, Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world..." So the grace of God is a teacher. Do you claim the grace of God and yet live an ungodly lifestyle? If we claim God's grace in our lives, we ought to let it teach us to deny "ungodliness and worldly lusts," and "live soberly, righteously, and godly, in this present world..."