We can look at the book of Numbers as a anthropological study of the Hebrew people. Or we can look at the descriptions in the book as micro-studies that reflect God's character and his heart for men and women. They also reflect ways we should respond to his holiness.
So in Numbers 4, we see all these men of the priestly tribe.
Each is called to serve God.
And each serves God in very specific ways.
The Kohathites do not serve in the same capacity as the Merarites. And the Merarites do not serve in the same way as the sons of Aaron.
Peter identifies Christ followers to God's chosen people, members of a holy priesthood (1 Peter 2:9). We are all called to serve God.
We just don't all serve him the same way.
It think it's profound that the Kohathites who basically tear down the tabernacle (remember, they are still wandering in the desert), are set apart for God. They are performing a sacred act.
And so are the Merarites, who move the stuff around.
Sometimes we negate our own priesthood because we think we play a small, meaningless task.
When we are serving God, nothing is meaningless.
And so whatever we are called to do, whatever we find ourselves doing, we must do it wholeheartedly, as to the Lord.
Remember, we are priests.