Umm, no, not the beginning of time, but only from the Fall of Adam. And it can't be all of our sins he at ones for, or else homosexuality wouldn't be a sin. The only sin he "died" for is disobedience to God. And does it really count as sacrifice if he gets resurrected anyway? It's not really sacrifice if nothing of value was lost. I'd say, more accurately, the people sacrificed Jesus, he didn't sacrifice himself. He didnt lose anything, in fact, he gained from his death. The people lost a teacher, a healer, a leader. That they just let it happen (at his request) shows the people were the ones who truly sacrificed. He just claimed the credit.