Why did the Lord chose the Levites to be the tribe that ministered to Him in the tabernacle? Listen to Him explain Himself,

Then the Lord spoke to Moses, saying:

“Now behold, I Myself have taken the Levites from among the children of Israel instead of every firstborn who opens the womb among the children of Israel. Therefore the Levites shall be Mine, because all the firstborn are Mine. On the day that I struck all the firstborn in the land of Egypt, I sanctified to Myself all the firstborn in Israel, both man and beast. They shall be Mine: I am the Lord” (Numbers 3:11–13).

As you know the tenth plague upon Egypt was the taking of the firstborn by the Lord, and to commemorate that event that set Israel free from bondage, He required the life firstborn of man and animal, but rather than sacrificing a child, the Lord required that the tribe of Levi be dedicated to Him.

Similarly, God the Father gave His Son that we might be delivered from bondage to sin.