The literal meaning is Jesus Christ, His Sacrifice, our call to repentance and baptism. These are not metaphors.
Parker, when I was an atheist I began my search for God in the greatest temple of all, the mountains that surround me. There are more than a few people who view the entire world as the temple, as Jesus did establish the Kingdom of God here. So where else is a temple but where God dwells? You can enter any place with peace in your heart and find God. He is always here. He never leaves us.
The OT was a time when people were still divided from God, by the sin of our first parents. The Holy of Holies represented where God dwelt, the veil separating humans from God. It was a reality, not a symbolism. When Christ died, the veil was torn. Literally. We are no longer separated from God. There is no reason to build temples that are designed around an old covenant that we are separated from God. We aren’t. All that was foretold in the OT, including the temples, point to a Person. To God coming into the world and reconciling us to Him. To a new covenant.
There are many Catholics who as they pass by a church they cross themselves. This is a prayer, asking God to bless us and an acknowledgement that we are passing where God is Present. We give particular attention to churches because for us, this is where God dwells, quite literally, not symbolically or metaphorically, in the Real Presence of His Body in the Blessed Sacrament. We keep an eternal flame lit, near our tabernacles, where God dwells.
Some of our Orthodox brothers/sisters have shared how their churches are laid out specifically. The Orthodox retain a screen, between the people in the nave and the Blessed Sacrament. In the Cathedral I go to the screen is there as well. The joyous thing is, for all of us, is this screen is not separating us from God. The veil is torn. We receive God at every Mass where His Sacrifice is Eternally given on an altar that is consecrated to God and this purpose.