What was the purpose for circumcision?

Original reason for circumcision in the Old Testament

Genesis 17 states that God required that Abraham and those of his house to be circumcised as a sign (NET “reminder”) of the covenant between God and Abraham and those who succeeded him.

Why did God initiate this specific procedure? What was its meaning?

The Bible does not give a reason why circumcision was chosen over other possible signs. One observation is that because it was a private sign, perhaps it diminished the temptation of making inappropriate public signs (see Matt 6:6).

It is sometimes said that circumcision was commanded because of the health benefits it confers. While there is evidence that circumcision does confer benefits, it also has risks. The Bible makes no claim about the health benefits of circumcision, and in particular, Christians are commanded not to require circumcision of others (Acts 15:19-20), so any health benefits cannot have been the primary motivation for the original commandment.

Conversely, where medical reasons are proposed for infants, Paul gives very clear warning against circumcision for Christians for religious reasons:

² Mark my words! I, Paul, tell you that if you let yourselves be circumcised, Christ will be of no value to you at all. ³ Again I declare to every man who lets himself be circumcised that he is obligated to obey the whole law. ⁴ You who are trying to be justified by the law have been alienated from Christ; you have fallen away from grace. ⁵ For through the Spirit we eagerly await by faith the righteousness for which we hope. ⁶ For in Christ Jesus neither circumcision nor uncircumcision has any value. The only thing that counts is faith expressing itself through love. ⁷ You were running a good race. Who cut in on you to keep you from obeying the truth? ⁸ That kind of persuasion does not come from the one who calls you. ⁹ “A little yeast works through the whole batch of dough.” ¹⁰ I am confident in the Lord that you will take no other view. The one who is throwing you into confusion, whoever that may be, will have to pay the penalty. ¹¹ Brothers and sisters, if I am still preaching circumcision, why am I still being persecuted? In that case the offense of the cross has been abolished. ¹² As for those agitators, I wish they would go the whole way and emasculate themselves! (Galatians 5:2-11 NIV)

This statement also shows that the rest of law, which was built on circumcision, is passed.