Question:

I was told by a Sunday school teacher that Cain was fathered by Satan. I cannot find this in the Bible. Can you help me with the answer?

Answer:

"Now Adam knew Eve his wife, and she conceived and bore Cain, and said, "I have acquired a man from the LORD"" (Genesis 4:1).

For a man to "know" a woman is the older way of saying they had sexual intercourse. We still retain the idea when was say two people were intimate with each other.

Cain's father was Adam and Eve was his mother. And you need to find a teacher who actually reads his Bible. I won't trust anything this teacher said unless I saw it for myself in the Bible.