Lord to reveal Himself the answer is yes. Unless the Lord reveals Himself, the devotee cannot see Him, He reserves the right of being exposed or not being exposed. The yoga maya curtain is always covering the Lord, and in the Bhagavad-gita the Lord says, "I am not visible to everyone.'' Even in the material world, a man in the position of Presidentship is not visible to everyone. So one has to qualify himself by devotional service, then God will reveal Himself. So this Isopanisad mantra is an appeal by the devotee to move the veil of yoga maya or the glaring effulgence of Brahma so that the devotee can see Him face to face.
Letter to Citsukhananda, 28 April, 1970