“On Dec 8, 1714, The Turks invaded and declared war on the Republic of Venice and the Christian west. The Pope considered this a war against Christianity and therefore, called for a crusade in order to help the Christian princes of Venice. Still full of zeal from his previous interior illumination experience, Paul thought he heard the call of God, so, in 1715, at age 21, he joined the crusade; he thought that this might be a good way of giving himself to God. Paul saw this crusade as a way to shed his blood in defense of his faith and for all who believed in Christ. Since it was a war for the faith, he saw the crusade as a way to martyrdom.
In February, 1716, while he was on his way to the front lines he stopped at a Church in Crema and prayed before the Blessed Sacrament (which was being exposed during 40-hours devotion). During intense prayer, an inner voice assured him that God was not calling him to a bloody battle in warfare, but to spiritual warfare. Being an unpaid volunteer, it was not difficult to receive a discharge, and he was on his way home.”