I don't think God dealt differently. It has always been about faith and still is.
even the sacrifice of animals required faith to believe your sins were forgiven...and yet scripture says the blood of bulls and goats could never remove sin
you could say, I think, that the OT is a physical picture of spiritual truths revealed in the new...however, even those who broke the law for the right reason were not condemned.
people love to use the law as some sort of tool for dismissing everything else the OT reveals...(I don't mean you personally here)
there are folks on this forum who think the words of Christ do not apply to us at all...some time back, someone was teaching here that the Lord's prayer is not for us to learn from and dismissing much of what Jesus taught
that is the end result of mishandling the word