The Hebrew word for faith is "Emunah," which is of the same root as "Emet," or Truth.
So faith and truth are really the same word, or at least derived from the same root.
To believe is to recognize the truth of something, and to admit a truth is a matter of faith.
What we consider truth is almost always a leap of faith at some point.
–Rabbi Adin Steinsaltz
From "On Faith and Blessing" in In the Beginning by Rabbi Adin Steinsaltz