If we analyze the question, it can likewise be asked… Why did God NEED to tell Moses to build the Ark of the Covenant? Can He not talk to Moses directly? Was it NECESSARY for a Bronze serpent to be made for the healing of those bitten by snakes (Numbers 21:9), when He can heal us with just a snap?

Why does God, with all His power still use material things to talk to us? To convey His message? To show His love and power?

Why does a God who is a Spirit, need to be INCARNATED and be born, thereby acquiring a human body when He can save us just by His thoughts?

As humans… God knows that we need something tangible. He knows that we respond to what we see, what we hear, what we taste, and what we feel… He knows that for we are His creation, and He created these senses. In His wisdom, He chose that we communicate with Him thru His works. Not that He lives within the hand-made things. Rather, He talks to us, heals us, loves us thru them.