One might say that the cure of any suffering coexists with the suffering. So, instead of seeing an evil “useless” and “stupid” as it is generally thought to be, you see that the progress, the evolution which has made the suffering necessary — which is the cause of the suffering and the very reason for its existence—attains the intended result; and at the same time the suffering is cured, for those who are able to open themselves and receive.
The three things—suffering as a means of progress, progress, and the cure of suffering—are coexistent, simultaneous; that is to say, they do not follow each other, they are there at the same time.
Ref: Notes on the Way