Are spiritual experiences absolutely necessary to realise God?

No. There can be many roads leading to the same goal. One road may have many beautiful flowers on either side; another road may have only a few blossoms; a third road may have none at all. If three seekers each follow a different road according to their souls' needs and preferences, each of them will reach the Ultimate Goal.

Of course, experiences do give you additional confidence in yourself. They encourage you and energise you to march farther and farther. They also give enormous delight. And while you are having the experiences you may feel the presence of an invisible Guide within your being, pushing you towards the light of Truth so that you may be blessed with full Realisation.

But you can also have full and complete Realisation without so-called "experiences." Your expanding consciousness, as you grow into God, is itself a solid "experience."