Grace is GOD’s reward to people who have faith in Jesus’ sacrifice for their sins. GOD’s choice of whom to “reward” involves grace, which is forgiveness.
Nothing about forgiveness involves how nice you are. The gritty truth is that no one is ever nice enough. Not you, not me, not Billy Graham, and not Mother Teresa. No one.
“Nice” is a cheap way of saying that one can earn goodie points to offset whatever “mistakes were made.” That’s not the case. Bring GOD a “broken and contrite heart” when you realize that Jesus’ death was on purpose, so that your sins’ wages could be forgiven. If you can’t reach “broken and contrite,” just keep thinking about it. Not getting there isn’t because you haven’t been “nice” enough.