I used to think that meant "that ye present your bodies a living sacrifice" (Romans 12:1), which is very appropos socially and politically. Now, as an old man, I focus more and more on the internal, the psychological dimension of this cross.
Jung taught a generation of pschologists the
crucifixion of the ego. Familiar with that concept for many years, it's only now beginning to impact my thoughts in a significant way. I think I passed a milepost when I began to recognize and dislike my ego, my egocentricity. "No good (suddenly); it will feed nothing but your vanity."
"O wretched man that I am! who shall deliver me from the body of this death ?" (If you don't know the answer to that question, look at Romans 7:25.); you only need to ask!
I usually wake up an hour or two before Ellie (She works much harder than I do!). This morning in a state of grace I asked God to take me through the day walking in his light, and particularly to deliver and protect me from that (suddenly monstrous) ego.
Would you believe he did? The day was good. We do doggie-dog tennis, usually a real feeding chance for the ego. Not today! Like Ellie I was thinking about the others: where are they? What are their needs? How could they do better (I don't just mean tennis-wise)? What could I do to be their friend? The day was beautiful; everybody had a good time.
Since then I've been ignoring my ego every minute (or at least trying to remember to). I even believe that I may be beginning to crucify the ego.
Do you want to? Just ask him/her whatever.