Doubt comes in many shapes and forms. It doesn't matter how righteous or obedient you are, no one is spared from the attack of doubt. The question is not if, but when doubt will attack your faith in God and in His goodness. So how do we guard our hearts in the midst of doubt's onslaught? Let's take a look at the journey of Zechariah and his wife Elizabeth, as well as Mary the mother of Jesus. Let's see how the Lord used their stories to show us how to guard our heart when we face unbelief.