St. Peter was called Simon before joining Christ. He was an average fisherman. Married with two children. It was Jesus who named him Peter. The Lord called Peter to apostolic service once the latter's faith and determination took shape.
After the coming of the Holy Spirit, St Peter went on six trips. He taught about Christ in Samaria, Judea, Galilee, Caesarea, Syria, Antioch, Phoenicia, Cappadocia, Galatia, Pontus, Bithynia, Troy, Babylon, Rome, Britain and Greece. He ordained his most devout disciples as bishops and presbyters. Church tradition ascribes the epistles First and Second Peter to the Apostle Peter, dating back to the years 63 and 67 A.D.respectively.
St Paul before becoming an apostle was named Saul. He was born into a noble family in Tarsus, Cilicia and had all the rights of a Roman citizen. Saul was brought up in the atmosphere of strictness and beloned to the Pharisees. Having received solid education for his times, he would develop a sense of hatred towards Christians. It was Jesus who radically changed Saul's religious beliefs, and the course of his whole life.
One day when Saul was on his way to Damascus to fight local Christians there, the Lord appeared before Saul and told him to become His servant. Saul's fellow travellers despite hearing some sounds could not understand the words. Saul himself could not see anything after being enlightened by the Divine Light.
As a result of this encounter, Saul became spiritually enlightened and was baptized. He became Paul. Apostle Paul began to spread the Gospel by travelling from country to country and sending out Letters. The Good News took him to Palestine, Phoenicia, Syria, Cappadocia, Galatia, Lycaonia, Pamphylia, Caria, Lycia, Phrygia, Macedonia, Italy, and to such islands as Cyprus, Lesbos, Samothrace, Samos, Patmos, Rhodes, Sicily etc.
Speaking of Christ, St. Peter and Paul converted thousands of people to faith. In addition, the Lord gave the apostles the power of the word so the dead were resurrected, the lame began walking, the sick were healed.
Both of the apostles died as martyrs on the orders of the pagan Roman emperor Nero. Apostle Peter was crucified on the cross. Apostle Paul -- being a Roman citizen -- was beheaded with a sword.
On the eve of this holiday, the fast which is called Petrivka ends. It starts on the second Monday after Pentecost (the day after All Saints' Sunday).
The next day after The Feast of Saints Peter and Paul, the Church celebrates the Synaxis of the Glorious and All-Praiseworthy Twelve Apostles of Christ.