Regarding the Islamic notion that the Trinity is a later theological development, allow me to proffer two citations:

1.

"Let US make man in OUR image": Three plural pronouns, (We, Us, Our) used 6 different times in four different passages: Gen 1:26; 3:22; 11:7; Isa 6:8.


2.John 10:33:

"I and the Father are one." The Jews took up stones again to stone Him. … Has it not been written in your Law, ‘I said, you are gods’?"

when God speaks, God use We/I/Us/Me, but you can NEVER find verses referring to God as “They/Their”.

Then God said, “Let Us make man ‘in Our image, according to Our likeness’; let them have dominion over the fish of the sea, over the birds of the air, and over the cattle, over all the earth and over every creeping thing that creeps on the earth.” Genesis 1:26

God was speaking with majestic authority thus using Us/Our in Gen1:26.

God said clearly “in Our Image according to Our likeness” referring to mankind becoming rulers and creators on earth. Not by any means using the physical of God to create shape of man and female, but rather figure-like to that of God having dominance over universe, but for mankind they having dominance over other living creature on earth.

And God created man ‘in His (notice verse do Not use THEIR) own image, in the image of God’ created He him; male and female created He them. Genesis 1:27

And if we use Pauline-Christian logic. Who's image was the verse referring to? Father? As Christians should know that Word and Spirit do not have image.
Do Christians believe Father/Word/Holy Spirit have image or all three were imageless?