He answered and said, “Who is He, Lord, that I might believe on Him?” – John 9:36

Saving faith is that which rests upon a knowledge of Him. This man said to Jesus, “Who is He, Lord, that I might believe on Him?” He was not one whose notion of faith was that he need not know what he believed. The Church of Rome seems to inculcate some kind of implicit faith (or credulity) which can exist apart from knowledge; but how can I believe that which I do not know? Paul puts it thus, “Faith cometh by hearing.” You must first hear and know what it is you are to believe before you can believe it; otherwise, your faith is vain, like that of the man of whom I have sometimes spoken, who said, “I believe what the Church believes.” “But what does the Church believe?” It believes what I believe.” “Then what do you and the Church believe?” “Why, we both believe the same thing.” That is not the kind of believing that can save the soul. It is through the knowledge of Christ that we are saved. To know Christ is sometimes said to be analogous to believing in Christ. You must know what it is that you have to believe; a faith that does not know is no faith at all. Read through the Epistles of John, and mark with your pencil every time the word “know” is used. The apostle makes that word “know” come in again and again, for a man must know that which he is to believe and hence this man says to Christ, “Who is He, Lord, that I might believe on Him?”~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2667.cfm