This is a very clear and understandable definition of emuna by Rabbi Lazer Brody:
"Emuna is the firm belief in a single, supreme, omniscient, benevolent, spiritual, supernatural, and all-powerful Creator of the universe, whom we refer to as G-d. He alone cares for each of us in a unique, tailor-made fashion according to our own individual needs. Everything that happens to us in life is the product of G-d’s will and personal intervention in our lives, which we refer to as Divine providence..........(read more)."