The temple building in the city of Jerusalem was just as real when Paul wrote that as it had been from the start of Herod the Great beginning to build it in 20 B.C. It was really there, it was really spectacular and gloriously impressive at 15 storeys high. It truly did function as intended, with sacrifices and offerings and a priestly system administering everything.
However, when Paul wrote that, the Roman army had not yet surrounded Jerusalem for the second time, to utterly destroy it, and to kill and capture the Jews. In 70 A.D., what Jesus prophesied in Matthew 24:1-2 about the destruction of that temple took place. Then Christians would understand what Jesus meant - that it was not just a symbolic destruction, but a literal one. Thereafter, the Jewish nation never again had a temple to worship in.
There is a parallel with how Jesus foretold his own death and resurrection. The disciples just did not get it - until after it happened. Once they saw the risen Christ, and he spoke and ate with them again, and once they saw him ascend bodily up into heaven, they got it. Same with the temple. They did not get it until after 70 A.D. Despite the immensely long, thick tapestry-like curtain in the temple being rent from top to bottom at Jesus' death, it did not seem as if anything had really changed. But, oh yes, it had, from God's point of view. The one perfect sacrifice for sin had been given by Jesus, and thereafter no more sacrifices at the Jerusalem temple would be worth anything, in God's estimation. Everything had changed.
This is where the Christians needed to switch their thinking from the literal and the fleshly to the symbolic and the spiritual. Just as it took them a while to grasp the significance of Jesus' death and resurrection, so it took a while to see how the literal temple had fulfilled its function and would be literally destroyed.
The Apostle Paul was God's man to explain such things to the new Christians. He combined the Hebrew prophecies with what Jesus did, and after A.D. 70, the Christians finally got it. God was no longer dealing with a physical, literal temple built from stones; he was 'building' a new, glorious Church with 'living stones' - Christians - with Christ as its foundation, and his sacrifice as the one needed to make the transformation from literal to spiritual, from dead stones to living stones - the people of Christ.
It is not the faith of Christians, however, that is to be contrasted with the literal temple in Jerusalem. A temple is where worship to God is offered. So when God turns people into 'living stones', it is his work alone that causes the switch from literal to spiritual, so that their worship of him is acceptable. His Spirit brings to life spiritually dead people, who then become these 'living stones'. Thereafter, their worship of God is accepted by God because the Spirit of Christ indwells them. Their faith is his gift to them, whereby they offer acceptable worship, for his glory. That is what verse 16 in the text states. And the earlier verses (from 9 to 15) use the analogy of them being "God's building", with Christ as the foundation upon which this spiritual building must grow.
"I beseech you therefore, brethren, by the mercies of God, that ye
present your bodies a living sacrifice, holy, acceptable unto God,
which is your reasonable service... Ye also, as living stones, are
built up a spiritual house, an holy priesthood, to offer up spiritual
sacrifices, acceptable to God by Jesus Christ." Romans 12:1 & 1 Peter
2:4-5 K.J.
you are God’s temple
andFor God’s temple is holy, and you are that temple.
What is unclear?