But this is a case of "Please don't look too close at our Jesus" by the attackers.
Trinitarian Jesus is not really the son of God, in any meaningful sense of the word "son". Nor is there really a "father".
A son, in the context of a dictionary definition, is:
1. a : a human male offspring especially of human beings
b : a male adopted child
c : a human male descendant
2 capitalized : the second person of the Trinity
3 : a person closely associated with or deriving from a formative agent (as a nation, school, or race) (Webster Online).
The first thing you note is that the second person of the Trinity is not a human male offspring, a male adopted child, or a human male descendant. He is something else.
So they made up a category: A name. Unconnected to anything which could mean an actual relationship.
A typical definition of the trinity follows along these lines:
The three Biblical doctrines that flow directly into the river that is the Trinity are as follows:
1) There is one and only one God, eternal, immutable.
2) There are three eternal Persons described in Scripture - the Father, the Son, and the Spirit. These Persons are never identified with one another - that is, they are carefully differentiated as Persons.
3) The Father, the Son, and the Spirit, are identified as being fully deity---that is, the Bible teaches the Deity of Christ and the Deity of the Holy Spirit. [Alpha & Omega Ministries]
The three persons are not "generated" by any one of the other persons of the Trinity, otherwise there would be a time when "the Father" would cease to be "the Father", because without a son, there can be no father. Arianism was the idea that the Son was a created being. That was the first great heresy of Christian doctrine, and required the Council of Nicea to resolve. This also led to the doctrine of the "two natures" of Jesus, to explain why he could appear to be human and yet be fully God as well. The "filioque" also came out of this, the idea that the Holy Spirit proceeds from the Father and the Son, instead of just the Father. The filioque doctrine is largely responsible for the split between the Eastern and Latin Churches in 1054 AD.
For Mormons, God is literally their Father, as he is the father of spirits (Hebrews 12:9), the creator of their pre-existent spirit (Eccl 12:7). Jesus is their brother (Hebrews 2:9-14), the son of God in a literal sense as well.
And let's not forget that Mormons believe we are the "offspring of God", the "genos" of God, springing from the same family line (Acts 17:29).
When John 1:12 tells us we can become the sons of God through accepting him. This, in the context, is the ability to return to God and see him, as John 1:18 notes, having been born IN THIS LIFE of God. So note that Acts, Hebrews and Ecclesiastes are talking about our birth BEFORE this life, John is talking about faith working to salvation in this life and in the future.
Jesus himself notes his deference to the superior position of God to him in that he notes in John 10 that the titles of "god" as used in scripture is actually superior to his title as "son of god" (John 10:33-36), though he was a son before his earthly birth.
So scripture says Jesus and humanity are all sons. It notes he had a superior pre-existence, was always a god himself. So how does a being who was always God,refer to another being as "the only true God"?
Jesus can only be a son if there is something about his relationship that makes him a male offspring or descendant of the father in the same way we are. Otherwise Hebrews 2 is meaningless. So too Hebrews 12.
The false doctrine of monolatry, of not understanding the henotheistic nature of there being multiple real gods has led to the false doctrine of the Trinity. The Father in the Trinity didn't really father anyone or anything related to Jesus. He is co-eternal with Jesus in the relationship of Father-Son. The title 'father' in fact implies existence prior to the son. It is simple word games to say the Father and the Son must be co-existent because the titles would be incorrect. Yet a father provides the source DNA in humans before the child exists.
What does the "Father" in Trinitarian thought provide the "Son" which is essential to his creation as a son?
Nothing. Because the Trinity is one god expressed as three persons, the roles of the Father and the Son may as well have been selected by slot machine. Nothing is unique about the Father or the Son that could not have been reversed prior to the Son's mortal incarnation. It is simply a role of respect: The Son respects the Father in Trinitarianism. He may have lost at "Rock, Paper, Scissors", and therefore is obligated to respect him. But there is nothing unique about the Father's being which could not be entirely demonstrated in the Son's being. Now the holy Spirit, he proceeds from the Father and (for some) the Son, so he is different. So too, the Son is "generated" from the Father, yet in Trinitarian theology the Father cannot be divided from the Son, since they come from the one essence of God, which they mutually share. Yeah, sure this is all the truth about God.
Since Jesus is generated in a way which does not come from either creation or produce existence, being a "Son" is truly the most meaningless use of a word which had, prior to the development of the doctrine of the Trinity, a clear and universally understood meaning. Do we really think all the New Testament authors decided to play word games, and ignore the clear meaning of the word, especially when Paul uses the concept of "heir" in Romans 8 to say our inheritance is identical to that of Jesus', that we are "joint heirs"?
It is true that Mormons have another Jesus. We have Jesus the Son of God, the Biblical Jesus.
We are not confused.