The historical-sociological writings of Rodney Stark concerning the phenomenon of religious conversion suggest that the process is much slower than usually realized; it usually takes hundreds of years before a whole nation or empire really comes to believe in a new religion, or a new variant of an existing denomination.
Also, much of this conversion has traditionally been due to 'natural increase' whereby the new religion (by one means or another) leads to higher rates of successful reproduction, out-growing the rival religions; and with the handing-on of religion from parent to child.
Also, new religions tend to grow from a basis in biological relatives of the founder; and relatives by marriage; and the spread is often by friends and neighbours rather than by missionary activity.
So that, in sum, traditional religious conversion has been much more of a 'family affair' than generally realized.
If such mechanisms applied today, it would mean that any resurgent Christianity could grow only a little faster than the rate of natural increase; and that it would probably take hundreds of years to convert the world.
But these are unprecedented times; and many of the principles that previously applied to traditional societies are no longer operative - and have even been reversed. And this particularly includes aspects to do with marriage, families and fertility.
Furthermore, all the major traditional religions are net-controlled by the 'New World Order' - which is leftist, secular, materialist/ anti-spiritual, and anti-religious (particularly anti-Christian.)
From this point of view the prospects of Christian conversion seem so bleak as to be all-but impossible.
Yet - exactly because these times are unprecedented; we might expect that God would ensure that there were also unprecedented opportunities for conversion, of a qualitatively different kind than in the past; and these might potentially be much faster than in the past.
In the past, religion was a social or group-level phenomenon; and without an institutional church it was hardly even conceivable and even less desirable - thus de facto impossible.
But now it has become possible to conceive religion - including Christianity - as a personal matter; and (although many would disagree) as a thing so simple that it could be apprehended and implemented by wholly personal experience and choice.
My understanding of Christianity is rooted in the Fourth Gospel, and the offer of eternal resurrected Heavenly life to all who 'follow' Jesus; where the 'following' is seen as something like a commitment spiritually to follow The Good Shepherd through death to everlasting list.
Something as simple as this can be understood by a child, and can be reasoned out by anyone who desires the end result (i.e. resurrection, eternal life, to dwell in Heaven).
It could, in theory, be adopted almost instantly, and by anyone who wanted it.
And such a Christianity could spread very rapidly... as fast as human thought.
That is, as fast as anyone who rejects what is on offer from the totalitarian global establishment - and instead (for instance by intuition, by contact with the Holy Ghost, by learning from the resources of Christianity that are almost ubiquitous) who decides that this is what he wants.
Maybe it is now possible for the world to become Christian as fast as thought, in a few moments?
Maybe that is what the demon-affiliated world-rulers most fear triggering by their actions?
Rooted in my personal understanding of Christianity - this ultimately-Good outcome, or something en route to it, does seem at least possible.