Faith implies knowledge. If there is absolutely no knowledge, there than can be no faith. There is no such thing as total blind faith.
Only partial blind faith exists.
I almost agree with you. If there is something out there of which you are totally unaware, there can be no knowledge or faith. You must have an idea in the first place so as to apply knowledge and/or faith.
The trouble is that there are two things in religion "a god" and "a concept of a god".
You and I both have a "concept of a god"; we have ideas as to what those words mean. Both you and I place, Yahweh, Christ, Zeus, Thor, etc in the category of "gods
of whom we have a concept
However, we must not confuse 'God Himself' with 'the concept of a god' - I know God Himself does not exist but the concept of God does exist. OTOH, you know he does exist and know the concept of gods
So your, " If there is absolutely no knowledge, there than can be no faith." should be "If there is absolutely no concept, there than can be no faith..." and the rest flows.
e.g. I can conceive of Australia and God but, as I know there is an Australia and do not know there is a God, I can only have real knowledge of Australia and only a concept of God.