Two prevalent errors about death - one materialist, the other spiritual

The mainstream and official modern view about death is that it is the complete annihilation of the person, after which nothing of that person remains. 

That is one prevalent error about death - it is the error of materialistic atheism. 

The other prevalent error is spiritual. 

It acknowledges that biological death of the body is not a complete end but that something of the person continues - and it concludes that "therefore" to the enlightened mind death is not really significant. 

This error states that any negative anticipation or attitudes - anything like fear, horror, or a sense of tragedy and loss - that people commonly feel concerning death; is based on misunderstanding. 

The erroneous assertion is that one who really understands death; does not regard death as important - it is just like going-to-sleep, passing through a door, just "another great adventure", moving to a "higher level"*. 

The spiritual error about death seems less obviously an error in the sense that it recognizes what humankind always has recognized (until very recently, and among a minority): that death is not the end of everything. 

But this recognition has a double-negative form: death is 1. not, 2. the end. 

So of-itself this does not move us towards a better understanding. 

The spiritual error is an error because it is an explaining-away; a denial of another universally-recognized truth...

That universally-recognized truth is that a human death death is significant, and indeed represents some kind of a tragedy. 

The spiritual error is in arguing that because death is followed by something better "therefore" we ought not to be sad about it. 

The error is in the "therefore" because this is a non sequitur; it does not follow. 

The world changes, we grow-up and apart, children grow-up and apart - all these may be inevitable and potentially good - but they are also sad - rightly sad: it is an impairment of sensibility if we cannot experience that sadness.

Such things, including death, are indeed tragic partly because they are inevitable, and especially when the change is overall good.  

It is tragic that overall good is attained only at the cost of particular loss and sadness. 

Mortal death is therefore significant, and rightly regarded as tragic; even when it is followed by something overall better; even when death is followed by resurrected eternal life in Heaven. 

And this is explicit in the IV Gospel - which is all about the new hope Jesus has made possible, of eternal resurrected Heavenly life; but the sadness, the tragedy of death - whether of Lazarus ("Jesus wept"), or the impending death of Jesus himself, is explicitly (as well as by the structure of the narrative) treated with full tragic significance. 

Jesus knows that he will be resurrected and attain salvation, as did Lazarus; but he is still saddened and grieved by the losses involved in death.

So; let Christians avoid both of the false extremes of arguing: either materially, that death is an end to everything; or spiritually, that death is insignificant in the scheme of things. 

*Note: I am saying here that - for all Socrates genuine nobility during his death, as recorded by Plato in Phaedo; the attitude he taught concerning death was erroneous.