16 The Faith of Our Fathers surmounts our churches and adorns our sanctuaries. We venerate it as the emblem of our salvation. "Far be it from me," says the Apostle, "to glory save in the cross of our Lord Jesus Christ."11 We do not, of course, attach any intrinsic virtue to the Cross; this would be sinful and idolatrous. Our veneration is referred to Him who died upon it. It is also a very ancient and pious practice for the faithful to make on their person the sign of the Cross, saying at the same time: "In the name of the Father, and of the Son, and of the Holy Ghost." Tertullian, who lived in the second century of the Christian era, says: "In all our actions, when we come in or go out, when we dress, when we wash, at our meals, before retiring to sleep, ... we form on our foreheads the sign of the cross. These practices are not commanded by a formal law of Scripture; but tradition teaches them, custom confirms them, faith observes them."12 By the sign of the cross we make a profession of our faith in the Trinity and the Incarnation, and perform a most salutary act of religion. We believe that on Easter Sunday Jesus Christ manifested His divine power by raising Himself to life, and that having spent forty days on earth, after His resurrection, instructing His disciples, He ascended to heaven from the Mount of Olives. On the Feast of Pentecost, or Whitsunday, ten days after His Ascension, our Savior sent, as He had promised, His Holy Spirit to His disciples, while they were assembled together in prayer. [004] The Holy Ghost purified their hearts from sin, and imparted to them a full knowledge of those doctrines of salvation which they were instructed to preach. On the same Feast of Pentecost the Apostles commenced their sublime mission, from which day, accordingly, we date the active life of the Catholic Church. Our Redeemer gave the most ample authority to the Apostles to teach in His name; commanding them to "preach the Gospel 12 De Corona, C. iii.