No human being can become God. There is only One God, and He is able to do all things, including entering into His creation at any time He desires to do so.
Christians and the Bible do not teach that Jesus became God in the incarnation because Jesus has always existed eternally as God.
What God did 2,000 years ago was to take on a body of flesh.
The Apostle John writes (italics are mine for emphasis),
1 "In the beginning was the Word,
and the Word was with God,
and the Word was God.
2 He was with God in the beginning.
3 All things were created through Him,
and apart from Him
not one thing was created
that has been created.
14 The Word became flesh
and took up residence among us.
We observed His glory,
the glory as the One and Only Son
from the Father,
full of grace and truth." John 1
In verses 1-3, John informs us that Jesus is God and has always existed as God.
In verse 14, John says God took on a human body.
The Word, Who is God, came down to earth and took the form of man to die for the sins of mankind.
That was Jesus, the Jewish Messiah.
As it is written:
"Therefore, as He was coming into the world, He said:
You did not want sacrifice and offering,
but You prepared a body for Me.
You did not delight in whole burnt offerings and sin offerings.
Then I said, “See — it is written about Me
in the volume of the scroll —
I have come to do Your will, God!” Hebrews 10:5-7
In the Gospel of Matthew, we read:
"See, the virgin will become pregnant and give birth to a son, and they will name Him Immanuel, which is translated “God is with us.” Matthew 1:23
The Gospel writer quotes Isaiah 7:14 but adds the words, "which is translated 'God is with us,'” to drive the point home. This Son will be "God with us."
The Apostle Paul writes,
5 "... Christ Jesus,
6 who, existing in the form of God,
did not consider equality with God
as something to be used
for His own advantage.
7 Instead He emptied Himself
by assuming the form of a slave,
taking on the likeness of men.
And when He had come as a man
in His external form,
8 He humbled Himself by becoming obedient
to the point of death—
even to death on a cross." Philippians 2
No man can become God, but God can take on human form because,
"... nothing will be impossible with God.” Luke 1:37
No one can kill God because God is Spirit and He is eternal.
God did not die on the cross.
Rather it was the physical body that Jesus inhabited which died.
"This is why the Father loves Me, because I am laying down My life so I may take it up again.
No one takes it from Me, but I lay it down on My own. I have the right to lay it down, and I have the right to take it up again. I have received this command from My Father.” John 10:17-18
And why did the Word of God take on human flesh?
He did it to fulfill the promise YHWH made in the Garden of Eden that He would set things right again:
"I will put hostility
between you and the woman,
and between your seed and her seed.
He will strike your head,
and you will strike his heel." Genesis 3:15
"Now since the children have
flesh and blood in common,
Jesus also shared in these,
so that through His death
He might destroy the one
holding the power of death—
that is, the Devil—" Hebrews 2:14
He did it because, while the First Adam had failed, the Second Adam would restore God's creation to Himself. While the First Adam had been self-seeking, the Second Adam would be perfectly loving and selfless:
"For as in Adam all die, so also in Christ all will be made alive." 1 Corinthians 15:22
"For we do not have a high priest who is unable to sympathize with our weaknesses, but One who has been tested in every way as we are, yet without sin..." Hebrews 4:15
"He Himself bore our sins in His body on the tree, so that, having died to sins, we might live for righteousness; you have been healed by His wounds." 1 Peter 2:24
Did Jesus do this unwillingly? Was He forced to do it?
"... keeping our eyes on Jesus, the source and perfecter of our faith, who for the joy that lay before Him endured a cross and despised the shame and has sat down at the right hand of God’s throne." Hebrews 12:2
"No one has greater love than this, that someone would lay down his life for his friends." John 15:13
Why would God suffer such agony and humiliation?
YHWH did it because He loves you.
“For God loved the world in this way: He gave His One and Only Son, so that everyone who believes in Him will not perish but have eternal life." John 3:16
See also Isaiah 9:6, Zechariah 2:11, Micah 5:2, and Malachi 3:1, among other verses