Christ was made a curse for us, that it was God's predetermined plan that he suffer and die at the hands of godless men. In context of the passage, it was the will of the Father.
The teaching that I draw from the passage is that it was the will of the Father - His predetermined plan - that Christ become flesh - become a curse for us - and suffer and die at the hands of godless men.
We certainly agree on this, which is a start. It was God's pre-determined plan that Christ become a curse. But we are still left with Deuteronomy 21:23:
'For He who is hanged [on a tree] is cursed by God.' This text was obviously in the mind of the Holy Spirit when He caused Peter to write,
'He Himself bore our sins in His own body on the tree.' Peter could very easily have written 'cross' instead of 'tree.' The reason he wrote 'tree' is to enforce the teaching, already made clear in Galatians 3:13, that our Lord was carrying a curse-- and it is the curse of God against sin, and
'sin is the transgression of the law' (1 John 3:4, KJV), and
'cursed is the one who does not confirm all the words of this law' (Deuteronomy 27:26). None of us keeps God's law (Romans 3:9-19; James 2:10). Therefore the curse of God is on all of us and we are all
'by nature objects of wrath' (Ephesians 2:1-3).
What is this curse of God? It is this: '
The soul that sins shall die,' and
'after this, the judgement.' What does that look like? 2 Thessalonians 1:9.
'These shall be punished with everlasting destruction from the presence of the Lord and from the glory of His power.'
But it was God's will that Christ should be
'made sin for us' (2 Corinthians 5:21). What does that mean? Isaiah 53:6 tells us:
'The LORD has laid on Him the iniquity of us all.' He is our
Surety. He undertakes for us in every respect that which we cannot do for ourselves (Romans 5:6-8). All the sins of God's elect were laid upon the sinless shoulders of Christ and He bore the penalty of them on the cross, and that
must include the curse, because we are told in Isaiah 53:5,
the chastisement for our peace was upon Him.' How could men and women be at peace with God if His curse were still upon them? He bore the wrath of God (remember Eph.2:3) and He bore the curse of God (remember Deut. 21:23), which were not upon Him as the sinless, spotless, beloved Son, but as the sin-bearer (cf. Leviticus 16:21-22), suffering outside the camp (Hebrews 13:12).
The result of this is that Christians are made
'the righteousness of God in Him.' This is Luther's 'great exchange:' our sins and wickedness are laid upon Him and He pays the penalty and bears the wrath and the curse, and His perfect obedience and righteousness are credited to them.
'But of [God] you are in Christ Jesus, who became for us wisdom from God-- and righteousness and sanctification and redemption.'