Complete surrender or earnest self-enquiry can only be effectively practiced by advanced devotees - For most people a preliminary period of mind purification, such as can be produced by japa or pranayama will be most useful

Saradamma

(from "No Mind- I Am the Self"):

Saradamma: People look at Swamy and me and think that realization must be relatively easy to achieve because we both realized the Self in a short time. However, we are exceptions. It is rare for someone to have the determination and dispassion that Swamy had during his sadhana, and it is equally rare for a devotee to be as God-intoxicated as I was.

Complete surrender or earnest self-enquiry can only be effectively practiced by advanced devotees. Even Ramana Maharshi sometimes said that self-enquiry was for ripe souls only. Most people need a long period of purification to get their minds pure enough for total surrender or effective self-enquiry. Devotees ask for grace to realize the Self, but most devotees are nowhere near ready for realization; if they were given a large amount of grace the shock would kill them. For most people a preliminary period of mind purification, such as can be produced by japa or pranayama will be most useful.