Pillar is actually used metaphorically to represent a permanent fixture - I do discern symbolism too!
This guy explains it better than I can.
Expository Files by Jon Quinn
["Interestingly, of the sixteen times the word “temple” is used in the Book of Revelation, only once does it refer to the church - Rev 11:1,2. The rest of the time, the word “temple” refers to the heavenly dwelling place, or sanctuary, of God. Heaven is His heavenly temple. Heaven does not contain a temple within it because the whole of heaven is God's temple, or dwelling place, containing His presence (Revelation 21:22).
So, if the “temple” here is heaven, what does it mean to be made a “pillar” there? It would not be for support. Rather, it would signify permanence. When one overcomes, he or she gains a permanent place in heaven (like a physical pillar would be a permanent part of a physical temple). Heaven becomes home eternally. (Note, this would not fit the church. In the church, I can overcome today but tomorrow I can leave the temple and forfeit my crown (See verse 11!)
So, Heaven does fit the context. Note text: (REV 3:12 - “I will make him a pillar in the temple of My God, and he will not go out from it anymore.” Jesus tells us that if we overcome now, for a little while, we will find a permanent place of joy, filled with wonderful experiences and great beauty and absolute confidence and security. In fact, this also fits with what the rest of the Bible says about heaven (John 3:36; 5:24; 14:1-3; Hebrews 5:9; 9:15; 11:10; 13-16; 1 Peter 1:4; Revelation 21:1-6; 22:5). Our hope of eternal life, of being forever with the Lord, motivates us to grow and endure and overcome so we may greet Jesus when He comes.. (1 Thessalonians 4:16,17)."]
The Church is the Bride of Christ. But did you think that the angel showed John a giant heavenly structure that meant the Church? Or was he first showing him, heaven first, where the bride would dwell and then the bride in these verses:
"The nations will walk by >>> its light <<<, and the kings of the earth will bring their glory >>> into it<<<. In the daytime (for there will be no night there) >>> its gates<<< will never be closed; and they will bring the glory and the honor of the nations >>> into it<<<; and nothing unclean, and no one who practices abomination and lying, shall ever come into it, but only those whose names are written in the Lamb’s book of life." Rev. 21:24-27
Do you see the distinction here???