Ah, the old “God must show himself to me!” in order for you to believe.
Here’s the thing, God did reveal himself to man, right from the beginning. And yet man still turned his back on God.
Despite this, God still wanted to save humanity, and promised a redeemer.
When Moses led the Hebrews out of Egypt, showing them the power of God first hand, they still turned on him. They still built a false idol to worship despite seeing that God existed.
This happens over and over throughout the history of the Israelites. They turn away from God, despite having him there in the tabernacle or temple.
So God destroyed the stone temple and gave us a new one, along with the New Covenant as promised. The Messiah, Jesus, who is the new David (King), the new Moses (Law), and the new priest in the line of Melchizedek, is the new temple. The Ark of the Covenant carried the 10 commandments tablets (the Law), the manna (the bread of life), and the rod of Aaron (the priesthood). Jesus became the new law, the bread of life, and the new head priest. Not just for Israel, but for all nations.