The Skodist Position on the Incarnation

The Thomistic position wants to agree that it is infallibly and with certainty from all time in this providential order that there will be a Christ. But where the Thomists would want to disagree is that precisely in stating that given the certainty of the incarnation, this doesn't mean that the certainty is eliding or moving away from also the certainty of sin. God's one sort of simple desire, the laity, whatever, in creating and governing the universe is that Christ come and that's not contingent upon anything. If we think about sin as being contingent in a certain sense, then it makes it seem like maybe this order would get Christ maybe it wouldn't according to the Thomistic position