Albert Barnes Commentary Mark 4:25

"For he that hath, to him shall be given: and he that hath not, from him shall be taken away even that which he hath." — Mark 4:25 (ASV)

For he that hath (see Barnes on Matthew 13:12).

The meaning here seems to be: He who diligently attends to my words will increase more and more in the knowledge of the truth.

But he who neglects them and is inattentive will become more ignorant.

He will forget the few things he had learned, and his trifling knowledge will be diminished.

Hath not. This means he does not improve what he possessed, or he does not make proper use of his means of learning.

That which he hath. This means what he had already learned.

By this we are taught the indispensable necessity of giving attention to the means of instruction.

This attention must be continued. It is not sufficient that we have learned some things or appear to have learned much.

All will be in vain unless we go forward and improve every opportunity of learning the will of God and the way of salvation.

So, what children are taught will be of little use unless they follow it up and endeavor to improve themselves.