At the Easter Vigil last night, the Old Testament text was where Abraham was told by God to sacrifice Isaac. Abraham had faith that God would provide the lamb, and that even in the face of this, He had faith that God would keep His promise through Isaac. God blessed Abraham, and promised him that his seed would be more numerous than the stars in the sky and the sands on the shore. But not only that, he said "your offspring will possess the gate of his enemies."
Who in the end is man's enemy? Death. Who defeated death? The promised one from Abraham's line -- Jesus Christ. So now when we enter the gate of death, Christ holds the gate for us, and it is no longer our Enemy's territory, because Christ is victorious over death.
Alleluia. He is risen!