Reading Luke 1 again.
I notice Zechariah loses the ability to speak because he "didn't believe what [the angel] said." Then later Mary gets big congrats on her lack of doubt: "You are blessed, because you believed that the Lord would do what he said".
My first thought is that if whether you are blessed or not depends on how quickly and easily you believe "that the Lord will do what he said", I am in a lot of trouble.
My second thought is that if an angel stood in front of me and told me just what it is that God is saying, I would doubt it a lot less...