God, who knows the heart, showed that he accepted them by giving the Holy Spirit to them, just as he did to us.
He made no distinction between us and them, for he purified their hearts by faith.
Now then, why do you try to test God by putting on the necks of the disciples a yoke that neither we nor our fathers have been able to bear?
No! We believe it is through the grace of our Lord Jesus that we [Jews] are saved, just as they [Gentiles] are.”
The whole point of Christianity was to recognize the fault that through the Law one does not become just in God's eyes. One does not "earn" salvation by "being good." We cannot buy our way into heaven. It is God's mercy and nothing that we could possibly accomplish on our own that saves us. Because even when we have not sinned as infants, we were not innocent.
Every Christian knows this. Every Christian knows that salvation can't be earned. But every Christian SHOULD know that freedom in Christ doesn't mean the freedom to transgress God's law...the freedom to sin. The 10 commandments are God's written definition of the law of love. Christians will obey God's commandments not because they think it will earn them salvation or favor in God's eyes, but because they have a heart of obedience and love God and his commandments.
1Jo 5:2 By this we know that we love the children of God, when we love God, and keep his commandments.
1Jo 5:3 For this is the love of God, that we keep his commandments: and his commandments are not grievous.
Let me ask you a question...is it okay with God if a Christian willfully and purposely commits adultery in an unrepentant fashion in deed and spirit? Of course it's not. Such a person probably isn't saved at all. Now why wouldn't a Christian do such a thing? It's exactly because as Christians we have God's laws written in our hearts and minds. That IS the promise of the new covenant:
Hbr 8:10 For this [is] the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people:
Hbr 10:16 This [is] the covenant that I will make with them after those days, saith the Lord, I will put my laws into their hearts, and in their minds will I write them;
Note how Paul compares the tablets of stone (the ten commandments) with the tablet of our hearts:
2Cr 3:3 [Forasmuch as ye are] manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshy tables of the heart.