Okay, so imagine you are making a cake. You need a recipe to tell you what ingredients to use and how to mix them together.
Now, in theology (which is like learning about God), people write books about what they believe and why they believe it. These books are like the recipes for understanding God.
But just like you wouldn't trust any old recipe you found on the internet, theologians (people who study theology) need to make sure the books they are reading are trustworthy and accurate.
That's where a justification bibliography comes in. It's like a list of sources that someone has used to make sure their beliefs about God are true and can be trusted.
Just imagine the justification bibliography as the list of all the ingredients you used in your cake recipe. If you used good ingredients, your cake will taste good. If theologians use good sources in their justification bibliography, their beliefs about God will be trustworthy.
So, in summary, a justification bibliography is a list of trustworthy sources that theologians use to make sure their beliefs about God are accurate. It's like the list of ingredients for a cake recipe, but for understanding God.