Catechism of the Catholic Church

Among all the words of Revelation, there is one which is unique: the revealed name of God. God confides his name to those who believe in him; he reveals himself to them in his personal mystery. The gift of a name belongs to the order of trust and intimacy. "The Lord's name is holy." For this reason man must not abuse it. He must keep it in mind in silent, loving adoration. He will not introduce it into his own speech except to bless, praise, and glorify it. (203, 435)