You can think your way to the point of seeing the need for yielding the phenomenal self to a higher power, whatever that might mean, but you can't do it, and should never pretend that you might. Every phenomenological or philosophical approach comes down to a core of Cartesianism, even if that is poeticised beyond recognition. You want to be there to observe every step, even the surrender of self, to be the witness of your own death, writer of your own obituary. For that you would need grace.