Grace came before times eternal, thus, before mankind was put on earth
Since Grace antedates mankind, it is available for whomever needs salvation upon its activation with the disobedience of Adam and Eve.
(9) who saved us, and called us with a holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before times eternal. 2 Timothy 1:9 ASV
Grace is a concept, a framework not something that can save us no matter how much we behave against Moses and the Prophets.
So, Grace saved both good and evil men before man was made by God to be on earth
Every day, grace is available for both the believing and the unbelieving. If the believing happens to sin and repents, grace is still available. If the unbelieving decides to believe, grace is still available to forgive the sins of the unbelieving.
Thus, none of us may claim that we are saved by grace. If that were true, all men are saved and there is no judgment of the wicked who fail to believe to claim his or her grace.
So, grace does not cancel any holy law or rule of God to keep, because we love God
The Law is holy because it contains disobedience which, if we do not follow we do not sin and commandments to follow which if we do them, turns us into a holy creature.
The Law also contains a list of behaviours of men which displease God, and as such, has no power to save but to condemn if we behave as forbidden or ignore other commandments like the commandment of holiness.
Grace existed before the Law.
We must believe 100% in God to claim the love and the grace of God for His free salvation
If we disagree with one decree of God in Moses, we do not believe in God because we agree with Satan in not doing what God wants us to do or in doing what God forbids us to do.
Total obedience to the will of God is emphasized in Ezekiel 33:13-20, James 2:10, 2:5, Deuteronomy 4:1-2, 5:32, 12:32, Matthew 5:17-18