The analysis of St. Paul’s life and his teaching leads to a conclusion that his mystical experience was the source of his active evangelization. Mystical experience is the highest state of spiritual life which depends on a person’s union with Christ. It is the result of the gifts of the Holy Spirit. It should not be considered as something extraordinary, but as “the high-class of ordinary Christian life” (cf. NMI 31). In the Bible we have two descriptions of spiritual events of Paul the Apostle, which according to the theology of mysticism, is a special kind of mystical experience. This experience usually followed his missionary trips. Both his mystical vision near Damascus (Acts 9, 1–19), and “catching up to paradise” in 2 Cor 12, 1–11 not only entirely changed his life morally and spiritually, but made him from a persecutor into a zealous apostle. Moreover, he was given the infused knowledge of Christian truths. Therefore the Apostle of Nations just after his conversion, before meeting St. Peter and others Apostles in Jerusalem, without any theological studies, started to proclaim the Resurrection of Christ and taught about redemption, fulfilled by His passion and death on the Cross. His original teaching was the doctrine about the Church as the Mystical Body of Christ. He received it from Jesus near Damascus directly when he had heard: “Saul, Saul, why do you persecute me?” By these words Christ identified himself with the Church. St. Paul’s love of Christ in way exceeded his faith, so he treated God’s love as the sense of human life. His mystical inspirations led him to active evangelization, and he also teaches about human body as the temple of the Holy Spirit. According to the teachings of the Carmelite Doctors of the Church (St. John of the Cross and St. Therese of Jesus), in mystical experience a Christian is changed into Christ, according to Galatians 2, 20. His spiritual anthropology is based on the conversion of an “old” man. It reflects in the mystical experience as a passive cleaning of senses and spirit. St. Paul’s mystical experience is the source of his whole missionary activity. This mystical mission was based on Christ’s calling, infused knowledge and merciful love. Mystically united with Christ, St. Paul accepted his salvational mission. He became a splendid example of missionary spirituality. As John Paul II teaches in encyclical Redemptoris missio, it is expressed “in the fullness of life in the Holy Spirit”, which makes us internally similar to Christ (No. 87). Following this, only a mystic, according to Paul, can evangelize effectively. It proves all the great missionaries, relating evangelization with personal sanctification.