Reflecting with Rabbi Reichman

The root of the word nisayon (challenge) is neis the Hebrew word for miracle. We are therefore left with two seemingly contradictory views. Either a nisayon is within one’s capacity, which means that it is NOT truly a miracle if one overcomes it, or it does require a miracle to overcome, in which case it is not within one’s capacity. How do we reconcile this seeming contradiction?

Why did Hashem create a world in which inspiration, physical sensation, and emotional delight always fade? What is the deep spiritual idea behind this pattern?