A covenant in the Bible is God’s promise to the human race. Two familiar ones are: Noah’s rainbow covenant (Gen. 9:8-17) and Abram’s “I will” covenant (Gen. 12:2-3). The most famous covenant is the Ten Commandments (Ex. 19:1-20); it was written in stone.
The prophet Jeremiah promised God was going to send a new covenant (31:31-34) and Ezekiel described it by saying, “I will remove from them their heart of stone and give them a heart of flesh” (11:19).
There is quite a contrast between the Ten Commandments and the promised new covenant. One is chiseled out of stone; stone is cold, hard, and unforgiving. The other one is a heart of flesh; hearts feel, love, and forgive.
When I think about my condition with God, isn’t this new covenant what I really need? Do I want to be judged by a law carved out of unforgiving stone or by a forgiving heart? And isn’t my black tar(ry) heart what really needs to be changed, and after all what would I do in heaven with a black tar(ry) heart? Jesus is the one who brings us our new heart, and that’s why they call him the great physician.