As Abraham called Word of God as LORD God, orthodox Christians do the same. Holy Trinity means God , Word of God or Christ and Spirit of God or Holy Spirit, ONE GOD, Three persons.
God is not limited like humans, one man one conscience or person.
To understand better think at somebody being in a 3D room and a 2D cinema screen universe. If one finger will be put into 2D Universe, 2D entities will say ONE, if Three fingers willbe put the 2D entities will say THREE but actually is one even if to the 2D UNiverse looks like three.
God revealed himself as Holy Trinity in Old Testament and New Testament , God , Word of God and Spirit of God and many Christians say, even if don’t comprehend how is this, because this is revelation form God we believe it, and because God revealed that we need to call every person of Holy Trinity as Abraham did, God, we do so. Also because it was revealed to us that by worshiping ONE God we need to worship every manifestation of God or every person of God, or we do so.
Ancient book about Adam and Eve written before even Judaism and Moses , like the one approximately named Fight of Adam and Eve with Satan , speak extensively about Word of God.
sacred-texts.com/bib/fbe/fbe007.htm
5 Therefore had God pity on them; and when He saw them fallen before the gate of the garden,** He sent His Word **unto father Adam and Eve, and raised them from their fallen state.
sacred-texts.com/bib/fbe/fbe008.htm
GOD said to Adam, "I have ordained on this earth days and years, and thou and thy seed shall dwell and walk in it, until the days and years are fulfilled; when
I shall send the Word that created thee, and against which thou hast transgressed,
the Word that made thee come out of the garden and that raised thee when thou wast fallen.
2 Yea,
the Word that will again save thee when the five days and a half are fulfilled."
3 But when Adam heard these words from God, and of the great five days and a half, he did not understand the meaning of them.
4 For Adam was thinking that there would be but five days and a half for him, to the end of the world.
5 And Adam wept, and prayed God to explain it to him.
6 Then God in His mercy for Adam who was made after His own image and similitude, explained to him, that these were 5,000 and 500 years;
and how One would then come and save him and his seed.
7
But God had before that made this covenant with our father, Adam, in the same terms, ere he came out of the garden, when he was by the tree whereof Eve took the fruit and gave it him to eat.
