The perception of Christianity, even sometimes from within Christianity, is that Christians are supposed to be perfect, righteous people. We equate God's ability to love and use us to our ability to perform at or close to His expectations.

Maybe that part isn't entirely untrue. The lie might be in what we think His expectations actually are.

God knows everything, so He most certainly knows we are nowhere close to perfect. He is aware of, and prepared for, all of our flaws. And He loves us anyway. And will gladly use us for His kingdom if we are willing.

Ironically, perhaps the only people God can't (or at least won't) use, are the ones who think they are perfect and righteous.