Sister … this is the position of those Sufis who have gone astray. It is the poetic condition of a Muslim to be in a state where he denies his worth to an extent that make his words appear to the onlooker that he has annihilated himself.
Some people actually take these words literally and embark on this self-extinguishing path. It makes them mad, or kills them.
On the other hand to deny ones own existence then we deny the worth in the Creating Force of God. It is true that on a scale of things that God looses no Greatness on account of our existence or not, but to deny that we have any worth or that we are not real is the same as denying the reality in Creation.
When effectively the belief ‘to be’ ends it will unequivocally end ‘being’ for us that is. Rather we should alter the thought of being to a condition of “being in submission” which reflects our insignificance with respect to God but at the same time acknowledges our ‘being’ in such a condition that to be in anything other than “submission” to God is an insult on ourselves and a dire error on account of our blindness.
So I agree we should not just “be” but I don’t think we should become ‘non-existent’ unless it is meant in another sense and that tie in the equation of relativeness to The One, which on any sensible terms is truly nothing or of no significance.