cross shall go before the King, pointing out Him that was formally
crucified.
St. Basil the Great, The Holy Spirit 27, 66 (375 AD)
Indeed, were we to try to reject unwritten customs as having no great
authority, we would unwittingly injure the Gospel in its vitals; or rather, we
would reduce Kerygma to a mere term. For instance, to take the first and
most general example, who taught us in writing to sign with the sign of the
cross those who have trusted in the name of our Lord Jesus Christ?
St. Augustine of Hippo, Homilies on John 11, 3 (416-417 AD)
If we should say to a catechumen: Do you believe in Christ, he will
answer, I do believe, and he will sign himself. He already carries the cross
of Christ on his forehead, and he is not ashamed of the cross of the Lord.
St. Augustine of Hippo, Homilies on John 118, 5 (416-417 AD)
What is the sign of Christ, as everyone knows, if not the cross of Christ?
For unless the sign be applied, whether to the foreheads of believers,
whether to the very water out of which they are regenerated, whether to the
oil by which they are anointed with chrism, or whether to the sacrifice by
which they are nourished, none of these is properly administered.
Catechism of the Council of Trent (1566)
Pt. II, Ch. III: Besides, that mark by which the Christian is
distinguished from all others, as the soldier is by certain badges, should be
impressed on the more conspicuous part of the body.
Catechism of the Catholic Church (1992)
No. 617:
The Council of Trent emphasizes the unique character of
Christs sacrifice as the source of eternal salvation and teaches that his
most holy Passion on the wood of the cross merited justification for us.
And the Church venerates his cross as it sings: Hail, O Cross, our only
hope.
No. 618:
The cross is the unique sacrifice of Christ, the one
mediator between God and men. But because in his incarnate divine