But of the son he says, “Your throne, O God, is forever and ever, the scepter of uprightness is the scepter of your kingdom. Heb 1:8
We must read the verse in context and if there is not support for one view over another immediately close by, then a wider search must be made. This is a primary principle of sound exegesis - letting the Bible interpret the Bible.
In this case, it’s clear Jesus is not 'the one true God' as evident from the next verse.
You have loved righteousness and have hated wickedness; because of this, God, Your God, has anointed you with the oil of exultation above your companions." Heb 1:9
Clearly there are either two Gods, or the translators have confused matters with their choice of capitalisation for God.
Verse 9 informs us of several things;
One God is superior to the other.
Only the superior God can anoint the other. Making Jesus the lessor G/god.
One has companions - which as a man, Jesus has all of humanity. As we know, he is the firstborn of many brethren. Col 1:15,18 (nothing to do with being firstborn prior to a Genesis creation, but of the dead - which is all humanity)
Jesus being sinless and victorious, he is rightly exalted above all other humans and the heavenly angels too.
One God has been exalted. The 'one true God, the Father' Jesus spoke about (and as the apostles often did) cannot be exalted higher than he is. Claiming Jesus is God means he is always God and not able to diminish his Godliness in any way that makes him somehow less God or not God. (Phil 2:6 does not support the idea that Jesus was God and became not God - so he could be tempted and die.)
We know Jesus' will differed from the Father. This makes sense of the 'loved righteousness' bit. Jesus chose to do right, to accord with the Father's will even though his will sometimes opposed God’s. God doesn't make these choices - He is right and good and love and his will to be holy is unquestioned and unequivocal.
From context of the v9, we see the depth added to v8 that is overlooked in favour of the proof-text reading of v8 in isolation.
Further, we see in v6
And again, when He brings the firstborn into the world, He says: “And let all God’s angels worship him".
Dispensing with the idea that Jesus must be God because he is worshipped. God is the one calling for worship of His holy, victorious son - and rightly so. Having His son share His throne is evident of the magnificent exaltation Jesus has received - he is worshipped as God's glorious son - not because he is somehow God, but because he is not!
Once again you see that Steve is claiming that the larger context disproves the Trinitarian reading but the exact opposite is true.
If we start with the earlier verses where angels are told to worship the Son. Yet only God is to be worshipped, indicating that the Son is God.
Then still contrasting the Son with the angels, these verses talk about Christ’s throne lasting forever and God anointing Christ above everything.
A clear contrast is seen between verses 6 and 7 and these verses; angels serve God, but Christ is on the throne. These verses are quoted from the Old Testament (Psalm 45:6-7) and refer to the triumph of Jesus as King; Christ's throne and rule will be established forever and ever. But of the Son He Says, "Your throne, O God, is forever and ever, and the righteous scepter is the scepter of His kingdom" (v 8).
This is one of the clearest statements of the Son being called God, proof of Christ's divinity and eternal status as the second person of the Trinity. Christ will rule over His kingdom with righteousness.
"You have loved righteousness and hated lawlessness" (v 9) refers to Christ's obedience on earth which made Him an inheritor of all.
"Therefore God, your God, has anointed You. With the oil of gladness above your companions (v 9)."
Because of Christ's obedience, He is anointed with the oil of gladness above His companions. As we will see throughout Hebrews, Christ's companions are fellow humans who are obedient. These faithful servants will be inheritors with Him, but Jesus is above all.
Christ obtained His inheritance, rule, and joy due to His life of righteousness of obedience; the same will be true of His companions. There is no joy greater than pleasing our Creator. The Greek word for companions is "metochous," from the root word "metochos." "Metochos" is an important word in Hebrews, used throughout (Hebrews 3:1, 3:14, 6:4). It means to be a participator, a sharer, or a business partner; the companions of Christ are those who share in His reward because of faithful obedience to Him in this life. If we share in His walk of obedience, then He will reward us by sharing with us His inheritance (the earth).