Since the Tabernacle is designed as a place of communion with God (Exodus 25:8), it makes sense that everyone should have access to it.
Within limits, of course.
For instance, Leviticus 1:2-3 says that people are allowed to bring their offerings to the Tent of Meeting, but that’s as far as they can go. Exodus 30:19-21 outlines various cleansing procedures for “Aaron and his sons” to enter the Tent, but even they couldn’t go into the Holy of Holies. Only the High Priest could (Leviticus 16:29-34), and even then, only once a year.
So why is this section in Numbers 18:1-7 included, then? This passage largely reiterates what we already know: The priesthood handles all the religious duties, while the other Levites assist them. We learned that in Numbers 3-4.
The answer is actually bound up in the fear of the Israelites in Numbers 17:13-14. At the end of a long string of judgmental activities, Israel’s mood shifts from “Look at the Tabernacle!” to “Oh no, the Tabernacle!” They didn’t want to come near it anymore. Their fear was too great.
To assuage these concerns, God places an added responsibility on the priests and Levites. In addition to their daily duties, they are also in charge of defending the boundary lines for access. The average Israelite may not know where they can or can’t go, but the priests definitely do. It’s up to them to stop it.
This explains why the priests in 2 Chronicles 26:16-20 are so adamant about King Uzziah not getting into the Temple. If they just let him waltz through the front doors, it’s their head on a platter alongside Uzziah’s.
God speaks to this concept in regards to our own life (which is fitting, since we are a “royal priesthood” according to 1 Peter 2:9). In Ezekiel 3:16-21, God says that if someone sins, they’ll bear the penalty for that sin. If we don’t warn them though, that’s on us, too. We have a responsibility to at least warn others from sinning.
That’s not the same as being responsible if they do sin, however. The priests in Uzziah’s day had an obligation to warn Uzziah; when he continued on, he was guilty and they were innocent.
Taking this a step further, when Judas committed to betraying Jesus, Jesus spoke out against it (John 6:70-71; Luke 22:48). Judas ignored it at his own peril and bore the brunt of his sin.
We need people like the priests in Numbers 18 in our own lives. Despite our own knowledge, it’s not only possible, but very likely, that we will make missteps in our life (and often) that we’re unaware of. Because of that, we depend on other people to warn us.
But we also need to be those people to others. Instead of just letting sin slide with a cursory “Well, they’re gonna do what they’re gonna do,” we need to step in and at least warn them.
If we don’t, we’re just as responsible.