Emunah

What exactly is faith? Faith is, for the most part, a convoluted idea. I mean, we know from the book of James that faith isn’t just believing there’s a God (James 2:19-20), but what exactly is it? 
Emunah. That’s the Hebrew word for faith, and its literal translation is “trust-grounded obedience.”
James has a lot to say about faith and works, and how the two go hand-in-hand. I wrote a lengthy entry about that, but I decided it would be best if you just go to James 1 and 2 and read it for yourself. Please do. You'll be blessed.
Bottom line, James says that you must be doers of the word, and not just hearers (James 1:22-25), and that faith without works is as dead as a body without a spirit (James 2:14-26). Keep in mind that James isn’t talking about just any works. In the first half of James 2 (verses 1-13), you see that these "works" are acts of obedience to the Lord’s commandments…the “law” as it is translated here.
This word “law” is the Torah, the first five books of the Bible. The Greeks had an advanced legal system, but they didn’t have anything comparable to the Torah. When translating the Septuagint, they selected the Greek word nomia, meaning “an unalterable law,” to represent this complicated Hebrew concept in a way that the Greeks might better understand.
But herein lies the problem. Torah is not law. The Hebrew word torah literally means “God’s teaching and instruction.” Further, its root word is orah, which means “light.”
The Torah is God’s teaching and instruction, given by Him to illuminate the path man should walk.
Jesus is God’s Word made flesh, the Torah incarnate—sent to dwell among us, to bring spiritual light in the darkness (John 1:1-14).
Trust-grounded obedience. Not obeying out of fear of punishment if we don't. Not even out of the desperation that comes with trying to earn His unmerited favor—those things can never be faith. No, there is no striving here. Only resting. This is obedience motivated by trust—in the One who died for us, redeemed us and restored us to Himself. Trust because of His lovingkindness, which births a desire to obey, not to earn anything, but simply because we love Him and want to please Him.
The hardest part of faith isn't the obedience. It's the trust.