Peter had been given a new understanding of God.  When Jesus Christ came into the world the understanding of Who God really is was complete.  Who God was, is and always will be did not change.  People often speak of the God of the Old Testament and the God of the New Testament as if it were different Gods.  There is,always was and will only ever be one God. Divisions between the people of the earth came about because of the sin of man, their thinking themselves to be more than what they were. When Christ came, He came to unify the world once more, but to unify them under His will.  Peter had come to understand this, and he was there to share this good news with Cornelius.  We today, all these years after the coming of Christ, need to affirm that same truth.  When God brings the mission field to us, we don't need to turn up our nose and say that there is one of them and hope they will go away.  We need to reach out to them in love and compassion. Not only will we often not go into all the world, we don't want all the world coming to us.  Peter did not go to Cornelius feeling superior but with a new understanding that God saw all people the same, sinners in need of grace or sinners who had accepted His grace and were called for a purpose.  Peter had said he was just a man.  We may look back on the apostles and early Christians as though they somehow greater than anyone who has come since.  Yet, as Peter said, so would they all have said,  we are just men.  What made them different was their relationship with Jesus, not as an earthly man that they walked with, but as an eternal Savior that they followed.  When we begin to horde the gospel, then we begin to see the world as us and them.  We want to make the gospel exclusive instead of inclusive.  We begin to want certain people destroyed instead of saved, and the gospel ceases to go into all the world.  We need to come to the understanding that Peter had that God is no respecter of persons.  Christ died for all, even those who crucified Him.