The answer is surprisingly simple: We read a children's Bible together! You can even download a Bible App for Kids (www.bible.com/kids) and read on a level the children will understand. Don't worry if the stories don't include all the details. This, like any educational process, is a stepping stone to build on later while bringing the realness of God to your kids.
In Deuteronomy 6:6-7 we find the foundation for teaching our children about God and the Bible:
If you aren't sure how to begin homeschooling, start with Bible time. Putting the Word in the hearts of our children is an invaluable education they will only learn from you at this point in their lives. And by starting your day reading the Scripture, you set the tone for the rest of your day! What a great example that is to our children!