Your comment reminds me of words from a great book called ‘The Screwtape Letters’ by CS Lewis. (The books is written as letters sent between demons, so when they say ‘Enemy’ they mean God.)
At one point, one demon says to another (about God’s relationship with humans, and why He allows humans to feel ‘down and empty’ as you say):
“He wants them to learn to walk and must therefore take away His hand; and if only the will to walk is really there He is pleased even with their stumbles. Do not be deceived, Wormwood. Our cause is never more in danger, than when a human, no longer desiring, but intending, to do our Enemy’s will, looks round upon a universe from which every trace of Him seems to have vanished, and asks why he has been forsaken, and still obeys.”
CS Lewis has the demons refer to this as the ‘law of undulation’ which affects the “amphibian” (haha) creature that is a human: “half spirit and half animal”:
As spirits they belong to the eternal world, but as animals they inhabit time. This means that while their spirit can be directed to an eternal object, their bodies, passions, and imaginations are in continual change, for to be in time means to change. Their nearest approach to constancy, therefore, is undulation-the repeated return to a level from which they repeatedly fall back, a series of troughs and peaks. If you had watched your patient carefully you would have seen this undulation in every department of his life-his interest in his work, his affection for his friends, his physical appetites, all go up and down. As long as he lives on earth periods of emotional and bodily richness and liveliness will alternate with periods of numbness and poverty…
This is a great book and I highly recommend it. One addition I’d make to the above is from St. Ignatius, in his 8th ‘rule’ for spiritual discernment:
Let him who is in desolation labor to be in patience, which is contrary to the vexations which come to him: and let him think that he will soon be consoled, employing against the desolation the devices, as is said in the sixth Rule…
<< Basically, the enemy will always try to tell you that consolations will never come again, or are so far away that you might as well give up beforehand. Whereas we are to hope that consolation will come soon, and continue in the holy actions we decided upon back when we were receiving consolations.
<<for a summary of the rules, and also podcasts on the subject of Ignatian discernment of spirits. Useful stuff for a Catholic!