I do not doubt that all those who have received Baptism anywhere and from whomever do have Baptism, as long as it was consecrated with the words of the Gospel and they received it without pretence on their part and with some degree of faith. However, it would not avail them for their spiritual salvation if they were lacking in that charity by which they might be implanted in the Catholic Church.
Saint AugustineIn the Catholic Church, there are many other things which most justly keep me in her bosom. The consent of peoples and nations keeps me in the Church; so does her authority, inaugurated by miracles, nourished by hope, enlarged by love, established by age. The succession of priests keeps me, beginning from the very seat of the Apostle Peter, to whom the Lord, after His resurrection, gave it in charge to feed His sheep (Jn 21:15-19), down to the present episcopate.
Saint Augustine