I opted not to include Scriptural references in my last post, because the post itself was about how to interpret Scripture so that it would have been question-begging. But these are passages that were in my mind when I consider that faith does not require epistemic certainty for the Word to be effective, nor does epistemic certainty confer faith. The effectiveness of the Word, the operation of divine revelation, cannot be judged epistemologically:
John 6:46 Not that any one has seen the Father except him who is from God; he has seen the Father.
Heb 11:1-3 Now faith is the assurance of things hoped for, the conviction of things not seen. For by it the men of old received divine approval. By faith we understand that the world was created by the word of God, so that what is seen was made out of things which do not appear.
Rom 1: 19-21 For what can be known about God is plain to them, because God has shown it to them. Ever since the creation of the world his invisible nature, namely, his eternal power and deity, has been clearly perceived in the things that have been made. So they are without excuse; for although they knew God they did not honor him as God or give thanks to him, but they became futile in their thinking and their senseless minds were darkened.
 "A sower went out to sow his seed; and as he sowed, some fell along the path, and was trodden under foot, and the birds of the air devoured it.  And some fell on the rock; and as it grew up, it withered away, because it had no moisture.  And some fell among thorns; and the thorns grew with it and choked it.  And some fell into good soil and grew, and yielded a hundredfold." As he said this, he called out, "He who has ears to hear, let him hear." 
And when his disciples asked him what this parable meant,  he said, "To you it has been given to know the secrets of the kingdom of God; but for others they are in parables, so that seeing they may not see, and hearing they may not understand.  Now the parable is this: The seed is the word of God.  The ones along the path are those who have heard; then the devil comes and takes away the word from their hearts, that they may not believe and be saved.  And the ones on the rock are those who, when they hear the word, receive it with joy; but these have no root, they believe for a while and in time of temptation fall away.  And as for what fell among the thorns, they are those who hear, but as they go on their way they are choked by the cares and riches and pleasures of life, and their fruit does not mature.  And as for that in the good soil, they are those who, hearing the word, hold it fast in an honest and good heart, and bring forth fruit with patience.
James 2:19 You believe that God is one; you do well. Even the demons believe -- and shudder.