Verses 17-20 stand out:
17 For there were many in the assembly who had not consecrated themselves. Therefore the Levites had to slaughter the Passover lamb for everyone who was not clean, to consecrate it to the LORD. 18 For a majority of the people, many of them from Ephraim, Manasseh, Issachar, and Zebulun, had not cleansed themselves, yet they ate the Passover otherwise than as prescribed. For Hezekiah had prayed for them, saying, "May the good LORD pardon everyone 19 who sets his heart to seek God, the LORD, the God of his fathers, even though not according to the sanctuary's rules of cleanness." 20 And the LORD heard Hezekiah and healed the people.The Law prescribed ritual cleaning before people could celebrate Passover. But the four tribes mentioned in v. 18 were in the northern kingdom which had gone so long without godly leadership that such parts of the Law were totally lost on them. But Hezekiah invites them to come back to the Lord and prays that God will be gracious.
And he's right on the money to do so. From the beginning, the whole point of the Law was to mediate a relationship between God and man, not just cold obedience to details. Of course, God prescribed those details for man's good, so as a person walked with God, he should have been submitting himself all the time to the whole Law. But what God always wanted was the Law to be on a person's heart (Deut. 6:6-7; 11:18-19; 32:46).
That is, what God really cares about is your heart.
Not according to the contemporary notion that suggests we are all basically good and all religions are basically the same, so as long as you are doing your best, God doesn't care too much about the details. No: God is jealous for our faithfulness like a husband is jealous for his wife's, and that is by no means petty. He wants us to serve Him and Him alone, and He hates anything that competes with that. And to be sure, that is certainly for our own good as there is no greater joy than to know the one true God.
What I mean is that God does not care so much that you go to church, read your Bible, or even, for some of us, have a paid pastoral position in a church, if your heart is not first bent on seeking to know Him above all else. If it is, then you should be doing those things- I am by no means rejecting the importance of discipline in our spiritual lives.
The point is this: set your heart on the Lord and Him alone. He will be gracious toward you when you miss the details.