The grace of God is a huge subject that must be fully and properly understood to experience the radical transformation from within by the Spirit. Without understanding, there can be no fire.
Truth is wood, Holy Spirit is fuel. Jesus is the truth. People who have been Christians for a long while but lack the real transformation from within, or struggling with status quo, a probable reason is not grasping the grace of God. It is often misunderstood to be cheap. Grace of God may be free, but isn't cheap. It's indispensable. People will perish without the grace of God. It's not an option.