Expressing evidences of God’s grace that you see in people’s lives is powerful. Rather than thinking about negative aspects of a person, remember that we are no better than them. We are all sinners in need of God’s grace; we need to believe in Jesus and his death on the cross and repent of our sin to be saved. God promises that when we do, we are made new; a brand new creation. That gives me hope.
We can do no good apart from him.
So when we see good in others, we know that it is because of Him. I’d encourage you to find ways to bless those you love (and those you find it hard to love) with words of encouragement. It will not only touch them, but the Lord may change your heart in the process.