After leading His people out of Egypt, God tells them that they must remember - and celebrate - that day for the rest of their lives. Every year, they must prepare a lamb, grab their walking sticks, don their sandals, smear some blood, and celebrate the Passover.
And from the second Passover ever, it doesn't go as smoothly as it sounds like it should.
It seems fairly simple to us: just do what God told you to do. But we are a people who don't have to worry about the kinds of things that Israel had to worry about. As a people not living under the law, we don't have to worry about things like cleanness and uncleanness, but it was the first thing on Israel's mind.
In fact, some men came to Moses right away and said, "Uhm, hey. We know the Passover is coming, but we are unclean. We really want to celebrate, though, because we know how great a thing this is. What do we do?" So Moses had to go ask God about the unclean among them, and God has this response:
Let them celebrate it next month when they are clean.
Notice that God doesn't say, too bad. Notice that He doesn't say it's their own fault. Notice that He doesn't say that they have to just stay cut off from this celebration and hope that next year is better. Notice that God doesn't judge the unclean at all.
No, what He says is, I will make provision for them, and they can celebrate.
We may not worry so much about unclean and clean...or do we? There are so many among us who believe themselves unworthy to come to God, for whatever reason. They think themselves unworthy to be part of the church. They sneak into our back rows after service starts and leave before it ends, trying not to be seen because their biggest fear is that they're not going to be welcome. They aren't going to get to celebrate the goodness of God. They aren't worthy. They aren't "clean."
That's why what God says is so important here. (Well, what God says is important everywhere.) Because God says even if you're unclean, there's a way for you to come. Even if you're unclean, you don't have to miss out. Even if you're unclean, the Passover - which we know is also the sacrifice of Christ - is still for you, too.
So...celebrate. Come. God says it's okay.