Why circumcision lost it's relevance after Jesus came?

I just studied this in Sunday School today. Look in Acts 15:1-19. The Pharises thought that the Gentiles should be circumsiced. But, the apostles and elders discussed it and Peter addressed this issue. It was decided that they should not make it difficult for the Gentiles who are turning to God.

Circumcision is still in practice until today, even when Jesus was a baby he had been circumcised too, so I do not think its' relevance is lost. Also, circumcision is hygienic for males. I think that is the main reason why all males should be circumcised, it is not merely a sign of covenant, but it is for health reasons too.

Circumcision is an everlasting covenant between Allah the Almighty Creator and Prophet Abraham PBUH the father of faithfuls, Jesus Christ PBUH was also Circumcised at the 8th day as written, circumcision didn't loss it's relevance after Jesus came as you already said, but after Saul of tarsus (or the so-called Apostle Paul) preached the false message to the wrong audience. now Christianity and the Church give more attention to Paul's deception than the teachings of Jesus Christ, some people also consider Paul the founder of current version of Christianity, where all the teachings of Jesus were canceled and the the Law was abolished by Paul when he preached the false message to the wrong audience.

I don't think its lost its relevance. Maybe the health reasons are why God wanted it done in the first place. Everyone thinks the rules, and laws are there for the hell of it. Like God said "You do it cause I say so." But I think that kind of attitude is a human attitude. I believe everything that God said was for a reason. It was for our own good.

It hasn't lost its relevance. Jews still practice it as a religious and cultural act -- pretty much for the same reason you say Muslims practice it. To Christians it was never relevant, rejecting circumcision was one of the points on which Christianity schismed from Judaism.