God doesn't need us--but He went through the effort to make a universe, and a world, and fill it with people, because He wanted to love. “The God who made the world and everything in it, this Master of sky and land, doesn’t live in custom-made shrines or need the human race to run errands for him, as if he couldn’t take care of himself. He makes the creatures; the creatures don’t make him. Starting from scratch, he made the entire human race and made the earth hospitable, with plenty of time and space for living so we could seek after God, and not just grope around in the dark but actually find him. He doesn’t play hide-and-seek with us. He’s not remote; he’s near. We live and move in him, can’t get away from him!" (Acts 17:24-28, The Message)
Even more remarkable is that He cares about each one of us, and uses individuals to build His Kingdom. If you get into His Word, you find that it talks about people--occasionally masses of people, but real, individual people. Usually we think of the long lists of people--family records, lists of the Temple staff, kings and politicians--as the most boring parts of the Bible and skip right over them as we read. I find them interesting for several reasons--one is that they are reminders that these are real people; nobody would have bothered to make them up! They are an indication of the authenticity of the writings, and that they are all known by their individual names.
We also have the stories of the people God tapped for works well beyond their human capacity--from Abraham, Jacob, Joseph, Moses, Joshua, David--and so many more. And then we see God do something in a whole new way, yet not completely different. We also see Him calling Tamar, Sarah, Hanna, Rahab, Ruth. and more; Women, called to do what women have always done (a very odd process, if you think about it), and the results were people called to do amazing things.
And then Mary. A woman called to do something ordinary in an extraordinary way. God didn't need to do this--He could have just gone on watching people try--or not try; do the good, the bad, or whatever, but always with a flaw. He could have continued to be patient, and love us anyway. But He wanted us to Grow UP. He wanted to share His Home with us--after cleaning us up from whatever isn't fit for His Presence. So He sent a part of Himself--through a human mother, like all of us came into the world. He showed what God is like--loving, forgiving, but also challenging and demanding. He even offered to live in us--so that we can live with Him. He doesn't need us--He wants each of us, unique individuals--to live up to His original design.