Ramana says

Talk 425. 

Will-power or any other is gained by practice (abhyasa).

Devotee: Is success not dependent on Guru’s Grace?

Maharshi: Yes, it is. Is not your practice itself due to such Grace? The fruits are the result of the practice and follow it automatically. There is a stanza
in Kaivalya which says, “O Guru! You have been always with me watching me through several reincarnations, and ordaining my course until I was liberated.” The Self manifests externally as Guru when occasion arises; otherwise He is always within, doing the needful.