Peter arrived at the home of Cornelius after two days' journey of about 30 miles along the coast road (Acts 10:24).  When he got there, Peter was personally greeted by Cornelius.  Respecting the Jewish tradition of not entering a Gentile home, Cornelius went outside to meet his guest.  Surely this man was from God: he was found in exactly the place Cornelius had been told in his vision (Acts 10:5-6).  

So, he fell at Peter's feet to worship him.  But Peter could not allow that, honestly saying he was only a man, not God.  He could not take any glory for what God was about to say and do through them (Acts 14:11-15).  Peter gladly went into the house where he found a large gathering of his friends and relatives.  Cornelius believed that God had instructed him to invite Peter to explain what God had to say; it was so important that the centurion invited as many people as possible to listen.  It was an honest and humble response to God’s opportunity to hear very good news.

As the crowd hushed to hear Peter, he started with a humble and honest confession.  God had dealt with his religious prejudice (Acts 10:15).  Previously, Peter would have never agreed to defile himself by visiting a Gentile; but God had shown him never to despise what He makes clean. (Although that initially referred to eating 'unclean' animals, Peter realised that God also meant that Gentiles were equally loved by Him; they had an equal right to hear and respond to the gospel.)  So, Peter had come in obedience to the Lord's command, and humbly placed himself as God's servant to help those Gentiles understand the gospel of Jesus.

If we are open to God, He will show us how we must humble ourselves in order to be used by Him (James 4:6-10).  We may start, like Peter, with big ideas of what we can do for Him.  But honest humility admits that it is He who has done so much for us.  He also has to overcome our prejudices before He can use us.   The reality is that we are all great sinners.  Apart from the grace of Christ, we have nothing to boast about  - except that Jesus loves every sinner and welcomes those who humbly admit it, and trust Him ... whatever their background (Colossians 3:11).