Cryptography is key piece of Defense in Depth in information security, and when implemented well works seamlessly and transparently to end users. It not used only for confidentially, but also authentication, integrity, and non-repudiation.
However crypto is often implemented poorly and a basic understanding goes a long way. Crypto basics are easy to understand. Although many people are afraid of trying to understand cryptography because it is sometimes non-intuitive and relies on heavy math, in fact its easy to get without the hairy math and without any leaps of faith.