Has grace always been an attribute of God?
Yes, grace has always been an attribute of God. When Adam sinned in the garden, it was God's grace that caused Him to seek out Adam and Eve, rather than letting them go or destroying them, and to reconcile them to Himself.
Les explains that grace has always been an attribute of God. Even though the four Gospels do not contain church doctrine or grace doctrine as we understand it—because God was still dealing with the nation of Israel under the law and covenant promises for 1,500 years before the cross—grace was already active in the garden. When Adam sinned, God's grace caused Him to seek out Adam and Eve, reconcile them to Himself, and not simply let them go or destroy them. Adam's faith restored fellowship with his Creator, and he will be in heaven, as will Eve.