My friend, who is an Arian, gave me this puzzling logic: God can't be tempted, but Jesus was tempted; therefore, Jesus is not God. Is this true?
For a Christian, it would be easy to spot this line of reasoning as a falsehood because it ends with a statement that contradicts the Bible. Jesus is God. "For unto us a Child is born, Unto us a Son is given; And the government will be upon His shoulder. And His name will be called Wonderful, Counselor, Mighty God, Everlasting Father, Prince of Peace" (Isaiah 9:6). This is the reason one of Jesus' names is Immanuel, which means "God with us" (Matthew 1:23). John states the deity of Jesus very clearly: "In the beginning was the Word, and the Word was with God, and the Word was God" (John 1:1).
So we need to move back and see where the flaw is in the reasoning.
"Let no one say when he is tempted, "I am tempted by God"; for God cannot be tempted by evil, nor does He Himself tempt anyone" (James 1:13).
If we look at I John 2:16, "For all that is in the world -- the lust of the flesh, the lust of the eyes, and the pride of life -- is not of the Father but is of the world," there are only three avenues for temptation: lust of the flesh, lust of the eyes, and the pride of life. Could God be tempted through the flesh? The answer is no because God has no flesh. "God is Spirit, and those who worship Him must worship in spirit and truth" (John 4:24). Can God be tempted through the desires of the eyes? Again, the answer is no because the universe already belongs to God. "For every beast of the forest is Mine, and the cattle on a thousand hills. I know all the birds of the mountains, and the wild beasts of the field are Mine. If I were hungry, I would not tell you; for the world is Mine, and all its fullness" (Psalm 50:10-12). So can God be tempted with pride? Once again the answer is no. There is none greater than God, so God cannot think more highly of Himself than He ought to think. "For I am God, and there is no other; I am God, and there is none like Me" (Isaiah 46:9).
This would be true with Jesus prior to his coming into the world, "who, being in the form of God, did not consider it robbery to be equal with God" (Philippians 2:6). But Jesus took on the form of man when he came into this world. "But made Himself of no reputation, taking the form of a bondservant, and coming in the likeness of men" (Philippians 2:7). With that from, the possibility of being tempted becomes real. "For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin" (Hebrews 4:15).
Yet, it would be a mistake to claim that because Jesus came in the flesh that he gave up his deity. He gave up his position of glory for a while, but he still remained deity. And he has returned to his position of glory. "Therefore God also has highly exalted Him and given Him the name which is above every name, that at the name of Jesus every knee should bow, of those in heaven, and of those on earth, and of those under the earth, and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father" (Philippians 2:9-11).