There is a very interesting point made in Reading Through Galatians by C.R. Hume. It brings up the interpretation of Paul’s statement in Galatians 5:12:
Gal 5:12 I could wish that those who trouble you would even cut themselves off!
In the context of this quote, Paul is talking about Circumcision. There were individuals, disciples of the 12 apostles, who were teaching that people must be circumcised to be saved. The entire book of Galatians is Paul’s response to this. In chapter 6, Paul writes:
Gal 5:11 And I, brethren, if I still preach circumcision, why do I still suffer persecution? Then the offense of the cross has ceased.
A few things to note: Paul states that he is being persecuted by those who advocate circumcision. Paul indicates that some people claim even Paul is teaching circumcision (a claim Paul is refuting). The one thing that Paul would have to stop in order to stop be persecuted is his insistence against circumcision.
Paul follows it up with this statement about the same individuals “cutting themselves off”.
But the word for “cutting off” is apokopto, which literally means to cut off. It is the same word always used in the Bible for chopping off things (like a body part):
Mar 9:43 If your hand causes you to sin, cut it off…
Mar 9:45 And if your foot causes you to sin, cut it off…
Joh 18:10 Then Simon Peter, having a sword, drew it and struck the high priest’s servant, and cut off his right ear…
Joh 18:26 One of the servants of the high priest, a relative of him whose ear Peter cut off, said, “Did I not see you in the garden with Him?”
Act 27:32 Then the soldiers cut away the ropes of the skiff…
The author of Reading Through Galatians writes:
The verb is not used metaphorically in the NT, and the middle form apokoptomai used here frequently refers to self-castration.
While modern Christians might want to sanitize Paul and say that Paul was referring to people cutting themselves off from Christianity. Paul was using a crude joke: “You know the people who want you to cut off the ends of your penis? I wish they would go all the way and castrate themselves.”