The experience cannot possibly be communicated / put into words. With a religious experience there is an awareness that there is something to be described but no way of doing so
St Teresa of Avila stated 'I wish I could give a description of at least the smallest part of what I learned but, when I try to discover so, I find it impossible
A religious experience can bring knowledge and understanding and therefore realisation of the truth. They provide insights into unobtainable truths despite being ineffable. Knowledge is grasped through the intuition and perception.