Moses was on Mt. Sinai with the Lord. The Lord began giving him instructions to build things that represent things in heaven. The Lord God gave Moses specifics and those specifics had to be followed exactly in order to not misrepresent the greater things in heaven.
The Ark of the Covenant; the table of showbread; the golden lamp stand; curtains of linen; curtains of goats hair; boards and sockets; the veil and screen for the holiest of holies; the bronze altar; the court of the tabernacle; and garments for the priest. All of these things show that the Lord is holy and that sinful man cannot come into His presence in their present sinful state.
One thing I notice about religions that claim the name of Jesus but do not either confess Him as Lord or trust in His promise of eternal life and sacrificial death as payment in full for sins, they will adopt some form of these things not understanding their purpose. Specifically with regards to priestly garments and priest being both ministers to the Lord and intercessors on behalf of the people.
Jesus sacrificed His body once for all time, His blood is covering for the sins of all who believe in Him. The veil was torn in two, the holiest of holies is open to all who trust in Him. He is our Priest forever, He makes intercession on behalf of everyone who comes to God through faith in Him alone. (Heb.7.25&10.19-22).
New American Standard Bible. (1995). The Lockman Foundation.