Before Jesus’s death, the cross was a symbol of a curse. In Paul’s eyes to be crucified with Jesus, means dying to the Law.
For through the law I died to the law, so that I might live to God. I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.
Christ redeemed us from the curse of the law by becoming a curse for us—for it is written, “Cursed is everyone who is hanged on a tree”—
So to take up the cross is bear the curse of the Law. It is not about sacrifice.
Hence what Jesus is saying is this: the Law cannot save you. You have to die to the Law to live for God.
Let me produce Galatians 2 in the Message.
The Message (MSG)
19-21 What actually took place is this: I tried keeping rules and working my head off to please God, and it didn’t work. So I quit being a “law man” so that I could be God’s man. Christ’s life showed me how, and enabled me to do it.
I identified myself completely with him. Indeed, I have been crucified with Christ. My ego is no longer central. It is no longer important that I appear righteous before you or have your good opinion, and I am no longer driven to impress God. Christ lives in me. The life you see me living is not “mine,” but it is lived by faith in the Son of God, who loved me and gave himself for me. I am not going to go back on that.
Is it not clear to you that to go back to that old rule-keeping, peer-pleasing religion would be an abandonment of everything personal and free in my relationship with God? I refuse to do that, to repudiate God’s grace. If a living relationship with God could come by rule-keeping, then Christ died unnecessarily.
This is how you should be taking the cross.