Is Jesus Christ mentioned as God in 1 John 5:20?

The verse says,

“And we know that the Son of God is come, and hath given us an understanding, that we may know him that is true, and we are in him that is true, even in his Son Jesus Christ. This is the true God, and eternal life.”

The argument of the Christ-is-God believers is that the one being referred to by the phrase “this is the true God” is Jesus Christ on the basis of nearest-antecedent-rule in grammar. Accordingly, the nearest subject to the pronoun “this” is Jesus Christ. Moreover, they also say that Jesus Christ is the “eternal life” (1 John 5:11) so the one being referred to by “eternal life” is the same being referred to by the phrase “this is the true God”.

Nearest Antecedent Rule

This grammar rule (I wonder if this rule really exists) is definitely invalid. One good example is the following sentences:
“X murdered Y. He was put in prison.”
Who was put in prison? X or Y? Does it make sense if the corpse of the murdered Y was put in prison?
How about the following sentences:
“X murdered Y. His remains lie in state at the funeral house.”
Now, who stays at the funeral house? Is it X or Y?

It is clear that we assign the subject to the pronoun based on the context of the sentences and NOT on the nearest-antecedent rule.
In Basic English Writing Composition Course, this ambiguity is corrected by adding words “former” and “latter” in order to clarify the meaning. The examples above should have been written as:
X murdered Y. The former was put in prison.
X murdered Y. The remains of the latter lie in state at the funeral house

How else should we understand this verse grammatically?

Grammatical Consistency

If we inspect the third person pronouns used in the verse, we should infer that these must be consistent.
“And we know that the Son of God is come, and hath given us an understanding, that we may know him that is true, and we are in him that is true, even in his Son Jesus Christ. This is the true God, and eternal life.”
What is being referred to by the pronouns “him” and “his” and “this”? It must be someone with a son named Jesus Christ. It is no other than the Father.

Compare spiritual things with spiritual

In order to understand God’s word, we must compare spiritual things with spiritual. As written,

“Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual.” 1 Cor 2:13

The safest way to understand 1 John 5:20 is to compare the verse with other verses of the bible especially those written by Apostle John himself.
In John 17:3, Jesus Christ was speaking to the Father saying,

“And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent”

Eternal life is knowing the Father as the only true God and Jesus Christ which was sent by the Father.

If we go back to 1 John 5:20, the main subject of the verse is knowing the Son of God, and knowing him that is true with a clue that He has a son named Jesus Christ.

If we consult the writings of Apostle John, who is this “true” that we should know? In John 8:25-27, Jesus Christ calls someone as “true”, thus,

“Then said they unto him, Who art thou? And Jesus saith unto them, Even the same that I said unto you from the beginning. I have many things to say and to judge of you: but he that sent me is true; and I speak to the world those things which I have heard of him. They understood not that he spake to them of the Father.”


THE ETERNAL LIFE

Christ-is-God believers especially the apologetics are fond of coining a descriptive phrase and assigning it to a PROPER NOUN that becomes an entity in itself. This is an extreme case of personification. One good example in layman’s lingo is the descriptive phrase “freedom of speech” which in many casual usage of the word becomes synonymous to “democracy”. However, “democracy” and “freedom of speech” are two different concepts. Although “freedom of speech” is associated in a democratic society but the key concept of democracy doesn’t say about “freedom of speech” but on system of governance.
Likewise, the apologetics insist that ETERNAL LIFE is CHRIST in 1 John 5:20 because Jesus is life (John 14:6). Accordingly, this eternal life is someone that we have seen and bear witness. (1 John 1:2).

In figures of speech, if X is Y, it doesn’t necessarily mean that Y is X. For instance, the statement “Time is gold” doesn’t not say that gold is time. The statement only wants to say that time is a precious as gold.

Similarly, when the bible says that Jesus is life, it doesn’t mean that life or eternal life is Jesus. It doesn’t make any sense at all if we loosely substitute and replace the phrase “eternal life” with “Jesus”.

Eternal life is a gift of God (Rom 6:23). It is a promise (1 John 2:25).
In John 17:1-3 and 1 John 5:20, we will inherit the ETERNAL LIFE by knowing the only true God who is no other than the Father and Lord Jesus Christ who is sent by the Father to us.