Hagar comes onto the scene about 10 years after Sarah was promised a child from God-but still, Sarah has no baby. Sarah is in a dark place right now. Each year had made it harder to believe God’s promise that she would have children. And finally, as if she begins drowning in her doubt, she decides to do things her own way. Sarah, 80 year-old Sarah, glances over at her Egyptian maid, Hagar. Hagar is young, dark, and beautiful. And she looks way more fertile than Sarah. Hagar looks like a solution to Sarah’s problem. So, Sarah grabs her by the arm and goes to Abraham and says, “Here. Get her pregnant. Then we can have a kid. Then God’s promises can happen.”
At this point in the story, Hagar names God. (She's the only woman in the Bible to do this!) She calls him "El Roi", which means "the God who sees." She didn't know God, she wasn't a super-Christian. But God saw her because he loved her, and that was all she needed.