Israel was instructed to circumcise all males as a symbol of their covenant with God. But that’s all it was—a symbol (cf. Lev. 26:41) . It was always designed to point to an internal reality. It was always designed to reflect a heart that delighted in being in covenant with the creator, a heart that delighted in being the friend of God.
But God is holy and man is not. And that meant and will always mean a heart that is committed to examining the soul with a surgical precision. As Luther said, “when God calls a man, he calls him to a life of repentance.” A Christian, a growing, Christ-exalting, joy-filled, follower of Christ is a person who learns from the biblical record that God delights in hearts that take repentance seriously. But it is hard work to take repentance seriously.
“Rooting out weeds from the fields of the heart is the most difficult part of repentance.”
(Peter Lange, A Commentary on the Holy Scripture)
Here’s how Jeremiah, the mouthpiece for God, puts it in the fourth chapter, the last half of first 3 and the first two lines of verse 4:
“Break up your fallow ground,
And do not sow among thorns.
“Circumcise yourselves to the Lord
And remove the foreskins of your heart,
Breaking up fallow ground is work. Circumcision is painful. And while both of these are metaphors they are “metaphors of difficulty.” And that is the point. It isn’t automatic. It isn’t easy. It isn’t without tears. It is rarely without pain and usually involves public confession as well as private prayer.
We are called to be brutally honest with the introspection of our hearts. To dig and mine, and pick our way through the dross of our sin and as the writer of Hebrews says,
Therefore, since we have so great a cloud of witnesses surrounding us, let us also lay aside every encumbrance and the sin which so easily entangles us, and let us run with endurance the race that is set before us, (Hebrews 12:1)
Running with endurance is hard. Taking sin seriously is hard. Repenting of sin is hard. Circumcising the heart is hard.
But if we want Him, if we want more of Him, if we want Him to be glorified in our lives, if we want the “nations to bless themselves in Him” (Jeremiah 4:2), then we will get serious about repentance.