Here is how I usually do it. Have your text graphic of your scripture. Then, use the pen tool to make points along your text going from right to left. Increase the width of the pen shape you just drew until it completely covers the text you want to write on. Then, have your pen shape write on but change the settings in the inspector to actually have it write off. Set it to be the mask and as it animates away it will look like you just wrote your scripture.