Complex sentence: Christianity asserts that God made a "New Covenant", which either replaces or exists alongside the Old Covenant of the Hebrew Bible, in which the Crucifixion of Jesus would atone for the sins of all who put their faith in him (Matthew 26:28).
Split into simpler sentences: Christianity asserts that God made a "New Covenant", which either replaces or exists alongside the Old Covenant of the Hebrew Bible. In this "New Covenant" the Crucifixion of Jesus atones for the sins of all who put their faith in him (Matthew 26:28).