“The rest of the Jews joined him in hypocrisy, with the result that even Barnabas was carried away by their hypocrisy.” (Galatians 2:13)
You are not an island. It matters what you do. Other people are influenced by you, and will imitate your choices. We see that here in Galatians 2. Peter, fearing the party of the Judaizers, who wanted all Christians to follow the Jewish Law, withdrew from fellowship with the Gentile Christians when the Jews arrived. But his decision affected more than himself.
Paul says here that “the rest of the Jews” — the ones who were previously with him in Antioch — followed Peter’s lead. And then, in a sad note, Paul said “even Barnabas” joined him. It pained him to see his beloved friend and ministry partner make such a decision — but such was Peter’s influence that so many others were affected.
You and I may not carry the weight of influence that Peter did, but we are each influential in our own circle. There are those who will take their cue from us: whether they are our church members, class members, work associates, family members, or others. This is why we must weigh every word and action. What you do, others will join. Make sure that what they are following in you is for the better, and not, like Peter here, for the worse.