At times, a person cannot engage in learning Torah
That is, a person so longs to be united with the supernal divinity, which cannot be formalized, that he distances himself from the material world and becomes unable even to take part in ordinary, formally structured religious activity.
That is, one must prepare one's soul to recognize and receive this light.
"Lines" and "points" are Kabbalistic terms. A "point" is an original idea, and a "line" is that idea's further development and revelation. The higher sefirot (and likewise, those worlds that are at a higher level than others) are points that contain an original idea in a compressed form; the lower sefirot are lines, disseminating these ideas. Here, then, Rav Kook tells us that the light of "heavenly desires" (that is, the original divine will, or Keter, which gives life to the universe), must gradually take its form by passing through the structure of worlds.
In the process of being drawn down, the supernal light must take form so as to be in harmony with the spiritually positive aspects of ordinary life, with the normal structure of the natural, lower world.
In this situation, the striving for supernal light will not reject the ordinary world (as may occur in the situation described at the beginning of this paragraph) but, rather, supplement, improve, organize, and enliven it.