Even in the instructions on how to build the sanctuary, God was trying to teach the Israelites that He is holy and precious. He wanted them to know that He was to be reverenced... not because His holy ego demands respect, but because as creatures, our best good comes when we respect our Creator.
One of the ways God communicated this in the sanctuary instructions was through the use of different materials. Three different building materials were used in the construction of the sanctuary and its elements: gold, silver, and bronze. Only gold was used to cover the "most holy" things, the things that held or signified God’s immediate presence.
The Ark of the Covenant, the Table (which held the Bread of the Presence), the Lampstand, and the Altar of Incense were all covered with gold. The more common areas of the sanctuary and the everyday altar for offerings utilized silver and bronze. In this way, the Israelites understood that the finest things in the sanctuary were the things that represented God Himself, and thus, that God Himself was the finest thing in their lives.
God still wants us to realize that He is the most precious thing in our life. No matter what other things of beauty surround us, He is the best, the cream of the crop. Everything golden is in Him!