In exploring WHAT the Holy Spirit is, might be a bit different from my ready answers about WHO the Holy Spirit is.
He is not just a force or energy as Galveston would teach. But WHAT is He ?
This is a difficult question to answer. I regard
"holy" as in
Holy Spirit to include the meaning that He is absolutely unique and there is NOTHING else in existence just like Him.
God ALONE is intrinsically Holy.
" ... for You alone are holy ..." (Rev. 15:4)
You cannot say "Explain what God is and give two examples."
Now to be fair, the Bible says that some things
dedicated to God or set apart for God are also holy. But intrinsically God ALONE is holy. Absolutely unique. Absolutely sacred in uniqueness.
These are my first thoughts in discussion WHAT the Holy Spirit is.