If it is agreed that Jesus died only After his mortal work was completed, then this has many implications...

Can we agree that Jesus died only when his earthly-work was complete? That his mortal work was done before he died? 

This is something that often comes to my mind as a subject for brooding! 

Because it would seem that Jesus allowed himself to be killed - this "therefore" implies that, by the time of death (or, at least, by the time of ascension), Jesus had already accomplished his mortal tasks. 

If so, it occurs that this has several implications which haven't really been taken on-board. 

On the one hand, Jesus had-done what he needed to do: reality had been changed in the ways that it needed to be changed. 

Whatever it was that Jesus made possible, had been made possible. 

On the other hand; it would seem that Jesus did not need to do whatever had not been done at the time of his death (or else he would - surely? - have stayed alive to do these things). 

So all the subsequent vast religious accretions of church, theology, practice, preaching... which were not done during Jesus's life; these would seem to be inessential.  

Of course; it may be that these post-Jesus accretions are in various ways better, usually helpful, may improve the chances of a good life and the choice of salvation... and so forth. 

But in terms of what we ought to regard as the requisite focus of following Jesus; it seems to me that everything vital must have been in-place by the time of Jesus's death.

If so; a consideration of what Jesus did and did not do while he was mortally alive; strikes me as a valid way of distinguishing the needful from the optional.