I can't get anyone to answer this honest question. All I get back is because the Bible says so. But there must be a reason for it. What is it? Here I will give you a reason why he had to be a man.
Romans says a man (Adam) caused sin to enter into the world, and also that a man would have to redeem it from sin. Romans 5:15 says “For if many died through one man’s trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many.” The Bible specifically says that a man must do it. The book of Corinthians makes the same point Romans does when it says “For since by a man came death, by a man also came the resurrection of the dead” (1 Corinthians 15:21).
Now it's your turn. Anyone?
God says Jesus is God, "Your throne, O God, is forever and ever, the scepter of uprightness is the scepter of your kingdom" (Hebrews 1:8).
You're question starts with a non-sequitor because NO scripture states Jesus was "made".
Regarding Romans 5:15 and 1 Corinthians 15:21, the following explains.
Jesus reveals Himself as truly God and truly Man at His discretion
Jesus Christ is truly Man (Luke 1:26-33) - the Son of Man, and Jesus Christ is truly God (Luke 1:34-35, John 8:58, John 20:28, John 5:18, John 10:30-31) - the Son of God.
Based on this Truth (John 14:6), Jesus Christ can refer to Himself as Man at his discretion and when He deems it is appropriate.
Furthermore. Jesus Christ can refer to Himself as God at his discretion and when He deems it is appropriate.
Here is an instance of Jesus, truly God, saying "I and the Father are One" (John 10:30) in which Jesus speaks in His capacity of God thus including both the person of Jesus and the person of the Father in the One True God.
Here is another instance, this time of Jesus, truly Man, saying "Stop clinging to Me, for I have not yet ascended to the Father; but go to My brethren and say to them, 'I ascend to My Father and your Father, and My God and your God.'" (John 20:17) in which Jesus speaks in His capacity of Man thus including the person of Jesus and His brothers in one (John 17:21). See, the Son of Man being the firstborn of the born of God persons (Romans 8:29, Colossians 1:15, John 3:3-8).
When Jesus says "For I have come down from heaven, not to do My own will, but the will of Him who sent Me" (John 6:38), then according to the Jesus, truly Man, Jesus does the will of the Father who sent the Son.
When Jesus says "Truly, truly, I say to you, before Abraham was, I AM" (John 8:58), then according to the Jesus, truly God, Jesus exists in eternity past which means Jesus is uncreated thus Jesus proclaims that Jesus is YHWH God for there is NO other that exists in eternity past (Isaiah 45:5).
We, children of God, can also refer to Jesus in his capacity as truly God as well as His capacity as truly Man. We can use context to make the distinction.
We, born of the Holy Spirit of God persons (John 3:3-8), are one in God (John 17:21) because of the indwelling Holy Spirit (John 14:16-17), thus God is One. We are the blessed beneficiaries of the Holy Spirit of God's work in us.
People who do not believe that Jesus is God are people who are not blessed beneficiaries of the Holy Spirit of God, so such people cannot see the Kingdom of God nor even King Jesus (John 3:3-8) for Who He is. You do not believe that Jesus is God.
Jesus is "I AM" before Jesus was begotten.
Jesus, truly God, always exists "before Abraham" as "I AM" (John 8:58) prior to Mary being told the beget event of Jesus, truly Man, prophecy by Gabriel "you will conceive in your womb and bear a Son" (Luke 1:34).