Prayer with effort

In D&C 9:7-8, we read

7 Behold, you have not understood; you have supposed that I would give it unto you, when you took no thought save it was to ask me.

8 But, behold, I say unto you, that you must study it out in your mind; then you must ask me if it be right, and if it is right I will cause that your bosom shall burn within you; therefore, you shall feel that it is right.

"Study it out in your mind" represents some effort on our part. Oliver Cowdrey had not quite understood that. Enos is someone who had understood. The tremendous effort he puts into prayer is something to contemplate.

All of these phrases are packed into that one chapter

the wrestle which I had before God (verse 2)

And my soul hungered; and I kneeled down before my Maker, and I cried unto him in mighty prayer and supplication for mine own soul; and all the day long did I cry unto him; yea, and when the night came I did still raise my voice high that it reached the heavens. (v.4)

I did pour out my whole soul unto God for them. (v.9) 

And while I was thus struggling in the spirit (v.10)

I prayed unto him with many long strugglings (v.11) 

after I had prayed and labored with all diligence (v.12)

I cried unto him continually (v.15)