There is no need for scriptures in pursuit of truth. The truth has to be proved without the scriptures. Until we get rid of all accumulated knowledge based on the body as self, the ignorance bound to persist. Thus for the seekers of truth, it is necessary to drop all the accumulated baggage to understand,assimilate and realize the non-dual truth.
The religious truth and yogic truth are individual truth not universal. Non-dual truth is universal truth.
The Bhakti and yoga are meant for the worldly mass ,who believes the body as self. Because they are based on the false self, within the false experience. Whatever is based on the body as self is bound to be falsehood.
The one who has progressed in his pursuit of truth does not require religion,concept of god or scriptures or guru. He is fully aware of the fact that the self is not physical and he has learnt to view and judge the three states on the base of the true self ,which is consciousness.
On the base of consciousness[soul] as self the three states are impermanent and mere mirage. Thus the man and his experience of the world which is present only in waking is unreal, same way as the dream. The dream becomes unreal when waking takes place. The waking becomes unreal when wisdom dawns.