While in seminary, I had the privilege (said with slight sarcasm) to write a 40-page chart over the book of Leviticus. It was a nightmare. However, through that process, I gained this super-detailed insight into the methods and requirements of the Old Testament sacrificial system. Of course, you should read it for yourself, but in the mean time, let me give you a summary: the people sinned; it broke their relationship with God; he provided a temporary solution through the shedding of animal blood; the people were right with God until they sinned again.

This system was so detailed. There were different animals to sacrifice for different things, and in different ways. They had to do it at certain times. They had certain annual festivals. They even had to make sacrifices for the temple and the altar once a year to cleanse them because the amount of sacrifices that were made throughout the year made even the temple and the altar unholy.

I cannot imagine being having to bring a sacrifice to God in order to have a relationship with him. I cannot picture the sights and smells that would have obviously taken place as the blood and bodies of countless animals were offered to the Lord.

I also cannot fathom why the God that created the universe would deem it fit to leave heaven and assume the form of a tiny baby  in order to grow into the perfect man who would become our final sacrifice.

While I do not understand everything there is to know about the Israelites’ sacrificial system, I can understand that God was doing something there. He was setting up this demanding and impossible system in order to teach his people that the blood of animals will never fully satisfy the payment for our sins.

For since the law has but a shadow of the good things to come instead of the true form of these realities, it can never, by the same sacrifices that are continually offered every year, make perfect those who draw near.
— Hebrews 10:1

See that? The “shadow of good things to come”? That’s Jesus. The law was always pointing to him.

And see what God was doing? He was showing the people that their sin must be taken care of hard, and there was no way that they could do it on their own. No way that the sinner, through any means, could make himself righteous.

But don’t feel bad for the Israelites, because we don’t always get it right either. We often fall into the trap of thinking that if we work harder, smile more, are nice to people who are different from us, attend church 35 out of the 52 Sundays in a year and read our Bibles (or at least buy one of those daily devotional calendars), that we can add all these things up to make our relationship with God equal something good.

And those things are fine and admirable, but if we fail to understand Jesus, all our work is just work.

When he said above, “You [God] have neither desired nor taken pleasure in sacrifices and offerings and burnt offerings and sin offerings” (these are offered according to the law), then he added, “Behold, I have come to do your will.” He does away with the first in order to establish the second. And by that will we have been sanctified through the offering of the body of Jesus Christ once for all.
— Hebrews 10:8-10

Jesus came to be our sacrifice. In one offering of himself, he made everyone that believes that he is who he says he is right for all time. He took the job that we have been trying to do since Adam and Eve made clothes for themselves in the garden and accomplished it on the cross. Once for all, for all time. This is why we celebrate the baby in the manager. Because babies don’t stay babies. And this one grew into our perfect sacrifice, simply out of love for us.