I think what Wiz is trying to say is that the whole soteriology of Xy is predicated upon the death of Jesus, who was innocent of any crime. We celebrate that sacrifice as a basic part of our worship. But, as he points out, the Bible states, "I desire mercy, not sacrifice" &c.
But where Wiz crosses the line is here: He says that we celebrate the sacrifice of Christ as a good thing. We don't! We don't celebrate the sacrifice at all, as a matter of fact. We celebrate what the sacrifice (in part) effected for humanity, not the sacrifice itself.
We have this religious season called Lent -- the forty days preceeding Easter. During that time we reflect on our own sinfulness and upon Christ's sacrifice. Our worship during Lent is penitential -- that is, we are sorry for our sinfulness that precipitated the sacrifice of Christ. Lent is not a celebratory time. We sing no doxologies, we refrain from the use of "Hallelujah," and we even cover the adornments in our sacred spaces. There is no festive processional before worship, and there are numerous opportunities for fasting and other spiritual disciplines. During Holy Week, the week immediately preceeding Easter, our worship takes on a particularly somber note, as we reflect on the events of the Passion.
On Easter, we celebrate loudly -- not the sacrifice, but the resurrection to life.
No. We do not celebrate the sacrifice of Christ. We are deeply sorry for the sacrifice -- that our own sinfulness brought it upon him. Our sinfulness was bought with a heavy, heavy price and we have no one to blame but ourselves.
But, we recognize that the sacrifice happened, and we seek to find God's will within it, and what meaning that might carry for the rest of us.
Wiz's premise is flat wrong on this subject. I'm sorry that he stresses so much over it. Perhaps if he took a good look at our theology, his heart could be put to rest on the matter.