The Old Covenant is compared to the New Covenant. The Lord God presented the Old Covenant to Israel at Mt. Sinai thru Moses on two stone tablets (Ex. 19-20) and the first five books of the Bible (though some are history). When Moses came down the mountain to present the Old Covenant his face was shown with the glory of God. This faded over time (Ex. 34:29-30, 33, 35). The old brought condemnation because the Israelites were unable to keep it for we all have the fallen sinful nature.
The Lord God presented the New Covenant to the world at Mt. Zion where Jerusalem is built thru Jesus, his Son. The Holy Spirit writes it on the hearts of those who believe in him. When Jesus ascended to heaven his face was shown with the glory of God. This never fades. The new brings righteousness because it solely relies on Jesus’s character and what Jesus did on the cross.
When I relied on myself for righteousness before God I had a veil over my heart. I tried to be a good person and so be accepted by God. I could not see God nor his Christ thru self-righteousness. I failed. I was separated from God.
Then God took the veil off my heart (16). Now I see Jesus sacrifice on the cross to atone for my sins. Now I solely rely on Jesus, who he is, and what he did for my righteousness. Now the Spirit of the Lord is in me. Now my relationship with God does not rely on me. I am free in Christ. I am free of the law and condemnation. I am being transformed into the image of the Son with ever-increasing glory (18). Jesus makes me competent as a minister of the new covenant (5-6).