2 Corinthians 3:6

3:6 who made us adequate to be servants of a new covenant not based on the letter but on the Spirit, for the letter kills, but the Spirit gives life.

2 Corinthians 3:14

3:14 But their minds were closed. For to this very day, the same veil remains when they hear the old covenant read. It has not been removed because only in Christ is it taken away.