You might branch out and read more that Paul's books. A number of saints were in the OT. Also note those at the temple - blameless is a common term. Even the oldest text, Job, speaks of these matters of being upright blameless VS wicked. Before the Law God spoke of those He considered friends of God. There are a number of passages that show what Paul said wasn't true. It's been about the grace of God since before man was created, as the stars were placed in the heavens and named by God. Even the grace of God at the fall and when Moses stood up for his brethren Israel when God wanted to destroy them."Anyone who repents to do the will of God does a good thing, so your last charge is nullified by the truth of the Christ and all the holy prophets of God from the beginning."
There isn't the first person who ever got to heaven by keeping those laws. And it certainly isn't going to be you.
But it is only because of His goodness that we find grace - it's not because of us, it's His goodness. I won't argue against that.
But I don't recall much about the grace of God towards those who refuse to even seek to do His will. As the parable of Jesus said of the king who went away and the subjects were not faithful... didn't the king say to bring those unfaithful servants before him and slay them (for their unfaithfulness)?
Luke records the sermon on the mount as condemning those who did nothing with His words, but I believe the Matthew account is the inspired record - and He didn't limit our responsibility to just do one or two things - as the Acts passage quotes Moses that we are to do whatever He says... Again, no one is perfect, but we do need to pay attention to what He said and get busy doing what we know.