Good post, addressing the OP. in the natural, a pillar is a support of the building. and we as a Spiritual house is a structure with support. example, Revelation 3:12 "Him that overcometh will I make
a pillar in the temple of my God, and he shall go no more out: and I will write upon him the name of my God, and the name of the city of my God, which is new Jerusalem, which cometh down out of heaven from my God: and I will write upon him my new name". to understand this, it's an allusion to something, an expression designed to call something to mind without mentioning it explicitly; an indirect or passing reference. here, a pillar is a defence for the structure of the Building, where it would not fall. in spiritual term a light to guide. as the apostle was with the Gospel.
Philippians 1:13 "So that my bonds in Christ are manifest in all the palace, and in all other places;
Philippians 1:14 "And many of the brethren in the Lord, waxing confident by my bonds, are much more bold to speak the word without fear.
Philippians 1:15 "Some indeed preach Christ even of envy and strife; and some also of good will:
Philippians 1:16 "The one preach Christ of contention, not sincerely, supposing to add affliction to my bonds

hilippians 1:17 "But the other of love,
knowing that I am set for the defence of the gospel.
Philippians 1:18 "What then? notwithstanding, every way, whether in pretence, or in truth, Christ is preached; and I therein do rejoice, yea, and will rejoice.
to understand this lets go to the OT, and get the meaning. and see who is the defense or the source of his strenght and who establish Paul in the Gospel.
Isaiah 52:1 "Awake, awake; put on thy strength,
O Zion; put on thy beautiful garments, O Jerusalem,
the holy city: for henceforth there shall no more come into thee the uncircumcised and the unclean". here Zion is mention as the holy city, and the name Zion means something.
Zion: H6726 צִיוֹן Tsiyown (tsee-yone') n/l.
1. (meaning) a monumental or
guiding pillar.
2. (location) Tsiyon (Tsion, Sion, Zion, Tzion) (as a permanent capital), a mountain of Jerusalem.
[the same (regularly) as H6725]
KJV: Zion.
Root(s): H6725
For a guide is to show or indicate the way to others. as a guiding light, a source of strength for those who overcome, those who stand tall in the defence of the Way of God, their strength is in Christ Jesus who write his name on them. as did when the first temple was built. lets understand this.
1 Kings 7:18 "And he made the pillars, and two rows round about upon the one network, to cover
the chapiters that were upon the top, with pomegranates: and so did he for the other chapiter.
1 Kings 7:19 "
And the chapiters that were upon the top of the pillars were of lily work in the porch, four cubits.
1 Kings 7:20 "And the chapiters upon the two pillars had pomegranates also above, over against the belly which was by the network: and the pomegranates were two hundred in rows round about upon the other chapiter.
1 Kings 7:21 "And he set up
the pillars in the porch of the temple: and he set up
the right pillar,
and called the name thereof Jachin: and he set up
the left pillar,
and called the name thereof Boaz.
the name Jachin, which signifies "he will establish", i.e. the house to which here was an entrance, so long as the pure worship of God should continue in it. Jesus is the DOOR or the WAY or the entrance to which is the WAY to Holiness.
and the name Boaz, which signifies "in him", or "it is strength", namely, in the Lord that dwelt there. These names were given by Solomon, which signified the pillar and ground of truth as of Christ himself, and the two natures in him. and of his royal dignity, signified by the crowns or
chapiters on these pillars which in Revelation 3:12 he writes his name on them. (One should read for themselves, 1 Kings Chapter 7 the building of the temple). it shows how decorated these Pillars were, whose legs are as pillars of marble, and in whom are righteousness and strength; which is no small encouragement to those who are entering into the church of God, which the temple was a type of. who, should they fear, being feeble and weak, that they should never fail. 2 Peter 1:10 "Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things,
ye shall never fall:
2 Peter 1:11 "For so
an entrance shall be ministered unto you abundantly
into the everlasting kingdom of our Lord and Saviour Jesus Christ.
2 Peter 1:12 "Wherefore I will not be negligent to put you always in remembrance of these things, though ye know them, and
be established in the present truth.
in these pillars, stood Jachin, to let them know the Lord will establish and settle them. Boaz to direct them to Christ, in whom their strength lies, so these pillars are an Allusion to the Lord Jesus who dwell in us by his Spirit. and we are "Rooted" and Grounded in Him.
I hope this helped.
PICJAG.