-- 2 Timothy 2:22b-26
Particular Churches are fully catholic through their communion with one of them, the Church of Rome "which presides in charity." "For with this church, by reason of its pre-eminence, the whole Church, that is the faithful everywhere, must necessarily be in accord." (St Irenaeus) Indeed, "from the incarnate Word's descent to us, all Christian churches everywhere have held and hold the great Church that is here [at Rome] to be their only basis and foundation since, according to the Savior's promise, the gates of hell have never prevailed against her."
-- CCC 834