Summary: There is so much that separates, so little that unites us...Living by faith is the key.
We ourselves are Jews by birth and not Gentile sinners; yet we know that a person is justified not by the works of the law but through faith in Jesus Christ. And we have come to believe in Christ Jesus, so that we might be justified by faith in Christ, and not by doing the works of the law, because no one will be justified by the works of the law. But if, in our effort to be justified in Christ, we ourselves have been found to be sinners, is Christ then a servant of sin? Certainly not! But if I build up again the very things that I once tore down, then I demonstrate that I am a transgressor. For through the law I died to the law, so that I might live to God. I have been crucified with Christ; and it is no longer I who live, but it is Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me. I do not nullify the grace of God; for if justification comes through the law, then Christ died for nothing.
In the early days of the church, leaders like Peter and Paul were busy finding out “who” they would be, and what they would preach and teach. There were problems. One preacher brought the issue to the light like this:
“You are a Jew,” said Paul to Peter, “but you used to live like the Gentiles, with no barriers between you and other Christians. Now you want the Gentiles to live like Jews, doing what you did not even do yourself!” 
Paul raised a ruckus with Peter because they both were Jews, but Paul had settled the issue on the basis of freedom in Christ – there was no difference between Jew and Gentile – everyone was the same in Jesus’ kingdom. On the other hand, Peter was doing what was expedient…when no one was looking he was eating pork barbeque with the Gentiles. When the Jewish brethren from Jerusalem showed up, he ducked-out the back door, lest he be seen eating with the “unclean”.
Paul had the intestinal fortitude to stand up to the big fisherman; he got in Peter’s face and bellowed, “Shame on ya’, big fellow!” Paul could do that because when it came to pedigree, he had it all. Paul was Jewish born, an educated man with powerful connections in high places. Peter was a nobody – just a stinky fisherman who could probably barely read. He had a lousy track record; he followed Jesus or denied he knew him depending on the circumstances. Paul told Peter he was being a hypocrite. It stung, but it was the truth!
Separation, arguments, prejudice, unfairness – what a tangled existence we human beings create for each other. When it comes to things that separate or divide people, the list is pretty long:
• Race – that’s always a big one these days.
• Lifestyle – there are messy people, clean people, fast and slow people; there are skinny people and generously piled “high and wide” people.
• Language – Press one to continue in English
• Region – I am one of the few “Yankee preachers” to ever have an ordination certificate signed by one Jefferson Davis!
• Age – the young person complains the adults have it made, while the aged shake their heads in disdain over the way youth is wasted on the young.