How do Trinitarians explain James 1:17, John 4:24 and John 17:3?

Firstly, when the word 'God' is used, it also needed to specify whom the 'God' is God to. God is the one who has authority to righteously judge over the ones to whom the God is God to. Moses was made a God to Pharaoh for a short period of time (Exodus 7:1). But Jesus is God to all humans. It is a misconception that Jesus and Father are completely equal when compared within themselves in trinity. The fact is, trinity doesn't claim that Jesus and Father are completely equal when compared within themselves, but only says that Jesus and Father both have 100% (equal) authority over humans. When compared within themselves, Father is greater than Jesus (1 Corinthians 15:27-28). But when compared with humans, both Father and Jesus have 100% authority over humans.

Secondly, regarding the verses you quoted, if you see the context,

• James 1:17 is about saying that God is not the one who tempts people but the people themselves get tempted by their own lusts. So, it is not about a comparison of Father's power with Jesus's power. I think it is a comparison of the Father's design vs human choices.

• John 17:3 is not a comparison of Father with Jesus being a competitor to Father but rather a comparison of Father with the description of the God described/believed by Scribes and Pharisees to be competitor. Jesus tried a lot to teach to them that Father (who loves people based on morality rather than nationality or race and who judges people based on the standard of pure moral conscience) is the only true God and the Jews (Scribes and Pharisees) were believing in some other description of God. So, Jesus is praying to Father so that they may believe that Father is the only true God in contrast with the God that they were believing in. Jesus is praying to Father so that they may believe that Jesus is the one that the Father (the True God) has sent, so that the people can believe in His words.

• John 4:24 is a comparison of God being Spirit vs the God that the Samaritans and the Jews had in their mind. The Samaritan Woman said they (the Samaritans) worship God on that mountain whilst the Jews worship God in Jerusalem. And Jesus was making the point that God is a Spirit and so the worshipping of God should be in Truth and Spirit, as opposed to worshipping on the mountain or in the Jerusalem.

So, if we see the context of these verses, I think it is very obvious that the writers had no intention to write about the validity of multiple persons being God at the same time.

James 1:17 does not contradict the trinitarian view. God is fundamentally good, and thus all his purposes would be good. That doesn't change, and he is still perfect. He does have different states of beings (insert complicated trinitarian explanation of how a 3 part one person system works)

John 17:3 Appears to only work under the specific ASV translation out of context. Allow us to read from the ESV in context.

When Jesus had spoken these words, he lifted up his eyes to heaven, and said, “Father, the hour has come; glorify your Son that the Son may glorify you, 2 since you have given him authority over all flesh, to give eternal life to all whom you have given him. 3 And this is eternal life, that they know you, the only true God, and Jesus Christ whom you have sent. 4 I glorified you on earth, having accomplished the work that you gave me to do. 5 And now, Father, glorify me in your own presence with the glory that I had with you before the world existed. (ESV)

Note the references to the Son and the Father, Jesus having authority, ect. This verse seems more to support trinitarianism, not refute it.

Let's (again) look at the last verse again in context.

21 Jesus said to her, “Woman, believe me, the hour is coming when neither on this mountain nor in Jerusalem will you worship the Father. 22 You worship what you do not know; we worship what we know, for salvation is from the Jews. 23 But the hour is coming, and is now here, when the true worshipers will worship the Father in spirit and truth, for the Father is seeking such people to worship him. 24 God is spirit, and those who worship him must worship in spirit and truth.” 25 The woman said to him, “I know that Messiah is coming (he who is called Christ). When he comes, he will tell us all things.” 26 Jesus said to her, “I who speak to you am he.” (ESV)

Again we can see that this verse doesn't contradict the trinity, rather it supports it. Note again the reference to the Father. Note also how Jesus is the "messiah".

So no, none of these verses really do much to refute trinitarians.

God is Spirit
One could argue that since God never changes God could not take on human form.

God is spirit, and those who worship him must worship in spirit and truth.”
(John 4:24 ESV)

Taken simply, this eliminates anyone who is human from being God. Yet interpreting God is Spirit, using our understanding of the physical and spiritual world leads to problems. For example, when a person speaks, it is their physical body which forms and causes words to be heard. Yet this certainty of the natural world cannot be used to define that which is spirit, since the Bible clearly states God speaks, despite being Spirit.

Moreover, the Bible has many events in which God is physically manifested. Man's first encounter with God is clearly one in which the experience is physical. If these are true, then God is Spirit cannot be understood to define God or narrowly to limit God's ability to interact with creation. Imposing a limitation would effectively mean God is not all powerful. In fact, if God does not change, then God's initial interaction with man must be seen as demonstrating God's intent for a relationship which includes physical interaction. We are in no position to use the Bible or our experiences, to define man's initial encounter as only "spiritual."

The "big picture" of the Bible describes how man's initial rejection of what God desires resulted in a temporary disruption, which God took upon Himself to correct. Where the man's initial rejection brought about a change determined by God, man's later rejection also brought about a change determined by God. Therefore the belief that God became flesh to restore what had been disrupted, is, in its most basic form, evidence of God's initial encounter and man's expectation of a final state.

"Only" True God
When Jesus prayed to His Father, and the Holy Spirit ensured that prayer would be made available to all who read the Bible, it is reasonable to assume He carefully chose His words:

And this is eternal life, that they know you, the only true God, and Jesus Christ whom you have sent. (John 17:3)
αὕτη δέ ἐστιν ἡ αἰώνιος ζωή ἵνα γινώσκωσιν σὲ τὸν μόνον ἀληθινὸν θεὸν καὶ ὃν ἀπέστειλας Ἰησοῦν Χριστόν

The word translated as "only" is μόνος. This word is first encountered in the Greek translation of the Old Testament in Genesis:

Then the Lord God said, “It is not good that man is alone; let us make him a helper corresponding to him.” (LXX-Genesis 2:18 NETS)
καὶ εἶπεν κύριος ὁ θεός οὐ καλὸν εἶναι τὸν ἄνθρωπον μόνον ποιήσωμεν αὐτῷ βοηθὸν κατ᾽ αὐτόν

μόνος means "alone." When Jesus prayed He chose a word which also described the initial condition of the first man. Therefore, "only" does not mean there is no other. It describes the temporary condition which exists because God not only took on human form; He did so on the earth He created.

This verse is the clearest expression of the Trinity, and it comes from Jesus, not Paul or John. The letter John writes serves as further evidence John also understood this meaning of μόνος:

And we know that the Son of God has come and has given us understanding, so that we may know him who is true; and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life. (1 John 5:20)
οἴδαμεν δὲ ὅτι ὁ υἱὸς τοῦ θεοῦ ἥκει καὶ δέδωκεν ἡμῖν διάνοιαν ἵνα γινώσκωμεν τὸν ἀληθινόν καὶ ἐσμὲν ἐν τῷ ἀληθινῷ ἐν τῷ υἱῷ αὐτοῦ Ἰησοῦ Χριστῷ οὗτός ἐστιν ὁ ἀληθινὸς θεὸς καὶ ζωὴ αἰώνιος

When writing after Jesus' return to heaven and making a similar description of a belief leading to eternal life, there is no mention of μόνος. Why would John omit anything which is essential to obtaining eternal life? Because that which was separated when Jesus became flesh, is no longer in that condition.

I don’t think Trinitarians feel that there is anything needed to refute in the verses you have raised (or in any Bible verses) because when you do not refuse that more than one person can exist in a single being, then the Father, Son and Spirit all are equally never changing, all spirit and all the only one God.

So when they originally debated these things it’s all semantics about what do we consider ‘a person’ is and what ‘a being’ etc. Of course I am using English and the original arguments were probably in latin with very specific wording to ensure all are God and God is a single One.

In practical terms it means the divine nature is shared by all three persons. In other words, never had a beginning, always everywhere, all knowing, holy, etc.

To raise a question that would provoke a Trinitarian response is if the Son or the Spirit seem to be denied the divine nature in some verse. This is what has caused doctrinal debates in the past and is usually denying either Jesus did not have the divine nature or denying that he was not fully human.