Holy Innocents, martyrs: "I lay down my life"

if we walk in the light as he is in the light, then we have fellowship with one another, and the Blood of his Son Jesus cleanses us from all sin.

-- 1 Jn 1:5—2:2

The Son of God, who came down "from heaven, not to do [his] own will, but the will of him who sent [him]", said on coming into the world, "Lo, I have come to do your will, O God." "And by that will we have been sanctified through the offering of the body of Jesus Christ once for all." From the first moment of his Incarnation the Son embraces the Father's plan of divine salvation in his redemptive mission: "My food is to do the will of him who sent me, and to accomplish his work." The sacrifice of Jesus "for the sins of the whole world" expresses his loving communion with the Father. "The Father loves me, because I lay down my life", said the Lord, "[for] I do as the Father has commanded me, so that the world may know that I love the Father."

-- CCC 606

Art: Giotto, Slaughter of the Holy Innocents