The context of John 1 concerns Christ’s divinity and his equality with God, not that Jesus is merely a “god”, as you would like to insist with your presupposition.

We see this by John placing both θεος and λογος in the nominative case, thus showing their equality. That fact is unavoidable. Otherwise, if Jesus was simply a god, it should have been θεον because λογος has the definite article and θεον would then be the direct object.

Further, since λογος contains the definite article at the very end of the verse and θεος is in the same case, the definite article can apply to both nominative nouns.

If you insist that Jesus was “a god”, how can Christ be called the Logos and yet be simply a “god” and not “the God?” That would make absolutely no sense because in that time, the Logos was seen as the divine reason and the divine mind. It would be absolutely bizarre to claim that this person was the Logos and yet was a lesser god than some other ultimate God. If that were the case, the ultimate God would be the Logos, not the lesser god.

Jesus elsewhere equates Himself as God (John 10:30). The Jews responded to this statement by picking up stones to stone Him.

A comprehensive list of Jesus’ statements have been compiled showing the truthful claim that He made that He was God: http://duncanf.blogspot.com/2007/07/did-jesus-claim-to-be-god.html

The other examples you gave are not the same Greek construction as found at John 1:1 and are thus not relevant to it. They are either objects of prepositions or a direct object that is anaphoric, in which cases no definite article would be required to translate them as “God” in English.

I grant that the prepositions do not need an article as I mentioned with “In (the) beginning.” By the way, τεκνα θεου in v. 12 is a genitive (possessive), not a direct object:

“But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name.”

If Jesus was simply a god how could someone believe in His name and then become an heir of the God? This could only be possible if they are both God.

The context of John 1:1 (and John 1:18) shows that a contrast is being made between “the God” and “god,” not an identification.

Even modern-day Greek scholars admit that the anarthrous, pre-verbal construction at John 1:1 is qualitative, not definite.

The other examples you gave are not the same Greek construction as found at John 1:1 and are thus not relevant to it. They are either objects of prepositions or a direct object that is anaphoric, in which cases no definite article would be required to translate them as “God” in English.

But the Greek construction of John 1:1 differs from your examples.

- The Pilgrim