And Jesus, full of the Holy Spirit, returned from the Jordan and was led by the Spirit in the wilderness for forty days, being tempted by the devil. And he ate nothing during those days. And when they were ended, he was hungry.

The devil said to him, “If you are the Son of God, command this stone to become bread.”
And Jesus answered him, “It is written, ‘Man shall not live by bread alone.’”

And the devil took him up and showed him all the kingdoms of the world in a moment of time, and said to him,

“To you I will give all this authority and their glory, for it has been delivered to me, and I give it to whom I will. If you, then, will worship me, it will all be yours.”
And Jesus answered him, “It is written, ‘You shall worship the Lord your God, and Him only shall you serve.’ (Deuteronomy 6:13)”

And he took him to Jerusalem and set him on the pinnacle of the temple and said to him,

“If you are the Son of God, throw yourself down from here, for it is written, ‘He will command His angels concerning you, to guard you,’ and ‘On their hands they will bear you up, lest you strike your foot against a stone.’ (Psalm 91:11-12)”
And Jesus answered him, “It is said, ‘You shall not put the Lord your God to the test.’ (Isaiah 7:12)”

-- Luke 4:1-12 (ESV)

Trinitarian scholars look this passage and reason:

• that the devil knew he stood no chance to tempt God, but wanted to at least give it his best shot, or
• that the devil only attack the limited human part of Jesus, and he tried to get Jesus to remove his human limitations so that he can no longer accomplish what he came to do as a human, or
• that we should ignore this passage because it is a satanic passage written with the purpose to cause doubt to the reader

However, Luke was not a santanist, and although we understand that the purpose of the devil's attack was to cause confusion and doubt, I believe we can still study Jesus words and reactions to these attacks.

Question: Did the devil tempted God or a human Jesus?

• If Jesus was God, he would have given the lead, yet Jesus was led by another Spirit (Matthew 4:1; Luke 4:1).
• God cannot be tempted (James 1:13), this would have been a pointless exercise for the devil (Matthew 4:1; Luke 4:2; Hebrews 4:15) if he knew Jesus was God.
• If Jesus was God, it would not make sense for the devil to request Jesus to proof that he is something lower than that (Luke 4:3,9). He would have rather requested Jesus to proof that he is God instead.
• Jesus defend himself with a scripture that is only applicable to humans for his own situation (Luke 4:4), which implies that he is a human too.
• Jesus was basically telling the devil that his fast is not over yet (Luke 4:4) and that he needs to be obedient to God ("man shall live ... by every word that comes from the mouth of God" -- Matthew 4:4). It does not make sense that Jesus would need to obey himself.
• The devil said that he can delivered the kingdoms to him (Matthew 4:9; Luke 4:5-6), but if Jesus was already God, he would have had no need for the devil to do that.
• A temptation is a desire for something that offers immediate satisfaction but have negative long term consequences. If Jesus was truly tempted, as written in Luke 4:2, then it would mean that Jesus did not have all authority at that moment, otherwise it would not have been a temptation to him (Luke 4:6).
• If Jesus was God, it would not have made sense for the devil to even try to ask Jesus to worship him (Luke 4:7) because God would have had no motivation to worship anything. But if Jesus was a human who know that he would be crucified, then this temptation could have been a convenient shortcut to bypass the suffering he knew he would endure and instantly receive instant power and glory with very little effort and still "save" humanity with the deal with the devil.
• Jesus did not tell the devil to worship him as Jesus, but instead warned the devil that only God should be worshiped which implies that he is not God. (Matthew 4:10; Luke 4:8)
• The devil quotes a scripture of God commanding His angels to protect Jesus (Matthew 4:5-7; Luke 4:9-11). If Jesus was God then the devil would have quoted the wrong scripture and Jesus would have had no need to respond. Yet, the devil knew exactly who and what God was (James 2:19).
• Jesus referred to God as Someone else (Matthew 4:6-7; Luke 4:12).