To reject the unworldly - and to assume (because it is an assumption: a metaphysical assumption, for which 'evidence' is irrelevant) that this-world is the only reality; is the modern, mainstream basis of all public discourse.
This-worldliness, as we can observe, is a recipe for fear, resentment and despair; because all that is of-this-world alone is subject to 'entropy'; by which I mean that all worldly things are evanescent, prone to degeneration, corruption, disease; and finally destruction and death.
But to reject the worldly, to regard it as wholly an illusion (maya) or a fake (the Matrix); and to be wholly un-worldly - is to deny any possible purpose or meaning to our mortal earthly lives.
This leads towards the conviction that this mortal life is futile (or a punishment); and the desire never-to-have-been-born; and to a death-wish - since only in the other-world can there be happiness, escape from suffering, and permanence.
In practice - the un-worldly tend either to seek death or to behave expediently in this mortal earthly life. Since, for them, everything is false and evil they cannot have any real basis for discernment between Good and evil in this world; between truth and lies, between beauty and horror, between virtue and sin... to them all is, alike, a temporary illusion.
Christianity is something different. Christianity is Not, however, a 'middle way' between worldly and unworldly - that is an error, with (as of 2020) spiritually lethal consequences.
Instead Christianity is properly a qualitatively different way: that recognizes the validity and necessity of earthly, mortal life; since such a life was chosen by Jesus.
Christianity also recognizes the necessity of death; since that is the path to the other-world of resurrection, immortality and Heaven.
So, Christians should neither be worldly, nor un-worldly; but should look for the consequences of their oft-suffering and always change-full worldly lives, in the joy and permanence of the next-world of Heaven; into which they will follow Jesus.