Some seed fell on rocky places, where it did not have much soil. It spring up quickly, because the soil was shallow.(Matthew 13:5)

Shallow! From the context of the teaching of this parble, it  seems that we must have something to do with the depth of the soil. The fruitful seed fell on "good soil"(v.8) or good and honest heart. I suppose the shallow people are those who"did not have much soil" those who have no real purpose in life and are easily swayed by a tender appeal, a good sermon, or a simple melody. And at first in seems as if they will amount to something for God, but because they do not have much soil, they have no depth or genuine purpose, and no earnest desire to know His will in order to do it. Therefore we should be careful to maintain the soil of our hearts.

On to broader fields of holy vision;

On the loftier heights of faith and love,

Onward, upward, apprehending wholly

All from which He calls you from above.