Many Christians attempt to use that passage to show that Gentile believers in the God of Abraham, Isaac and Jacob don't need to be circumcised. When read in context, however, we see a completely different picture!
Galatians 2: 1. Then after fourteen years, I went up to Urishlim with Bar-Naba and Titus also with me. 2. I went up because I was in a revelation, and I made known to them the Good News that I preached among the nations. I then explained to those who were considered to be something (great) among themselves, or else I labored in vain, or should labor. 3. Concerning Titus, who was with me and who is an Aramean, he was not compelled to be circumcised. (Aramaic English New Testament)
Unlike the contemporary traditions of Judaism in Paul's day, someone who follows Mashiyach is not immediately forced to be circumcised once they show interest, as this is something that is done according to the intent of a person's heart. Circumcision is a voluntary choice, just as it would also be unthinkable to force someone to be immersed (baptized). Every soul must willfully volunteer to fulfill their obligations as their soul is being matured by the Ruach haKodesh.
Paul clearly indicated that the requirement for circumcision has in NO way been negated. Circumcision is a demonstration of Faith and Obedience when a person does so according to the leading of the Ruach haKodesh, but NOT on the basis of social, peer, or status quo pressure.
Circumcision, like the Seventh Day Shabbat (which is a sign between YHWH and those who are His - Ezekiel 20:11-12), is another thing that sets us apart from "the world." We must remember that YHWH told those who wished to worship Him to do exactly the same as His Torah observant Hebrews did:
Numbers 15: 13 "'Everyone who is native-born must do these things in this way when he brings an offering made by fire as an aroma pleasing to the LORD. 14 For the generations to come, whenever an alien or anyone else living among you presents an offering made by fire as an aroma pleasing to the LORD, he must do exactly as you do. 15 The community is to have the same rules for you and for the alien living among you; this is a lasting ordinance for the generations to come. You and the alien shall be the same before the LORD: 16 The same laws and regulations will apply both to you and to the alien living among you.'"