Don't ever think that God was not gracious to Israel in the Old Testament, He was nothing by gracious and kind, and longsuffering toward them. And it was in the midst of their rebellion against Him that He gave them the promise of the New Covenant, in which He perfect all of the promises of it Himself, for their sakes. He didn't say that He had HAD with them, but instead, I will be gracious to you. "For I will be merciful to your unrighteousness." That's grace!