For when God forbids us to kill, he not only prohibits us from open violence, which is not even allowed by the public laws, but he warns us against the commission of those things esteemed lawful among men. . . . Therefore let no one imagine that this is allowed, to strangle newborn children, which is the greatest impiety; for God breathes into their souls for life, and not for death. But men, that there may be no crime with which they may not pollute their hands, deprive souls as yet innocent and simple of the light that they themselves have not given. Can any one, indeed, expect that they would abstain from the blood of others who do not abstain from their own? But these are without any controversy wicked and unjust. –Divine Institutes, 6:20 (307 A.D).

The Marvelous Power Of The Cross | Pope Leo The Great
Our understanding, which is enlightened by the Spirit of truth, should receive with purity and freedom of heart the glory of the cross as it shines in heaven and on earth. It should see with inner vision the meaning of the Lord's words when he spoke of the imminence...