I was taught to give attention to my sense of ‘I am’ and I found it supremely effective. Therefore, I can speak of it with full confidence.
But often people come with bodies, brains and minds so mishandled, perverted and weak that the state of formless attention is beyond them.
In such cases some simpler token of earnestness (like repeating a ‘mantra’) is appropriate.
After all it is the earnestness that is indispensable, the crucial factor.
‘Sadhana’ is only a vessel and it must be filled to be brim with earnestness, which is but love in action.
For nothing can be done without love.