What gives the Word of God authority is simply the fact that it is the word of God!
The first step towards the evangelizing of the world is the christianizing of the church.
A preacher who is too big for a little crowd would be too little for a big crowd.
We need to be preaching a dynamic Gospel and living firecracker lives.
I preach on specific sins because people are not convicted by sermons on sin in general. It was when our Lord said to the Samaritan woman, 'Go call thy husband...' (John 4:16), that she really faced up to her sinfulness.
The devil is not fighting religion. He´s too smart for that. He is producing a counterfeit Christianity, so much like the real one that good Christians are afraid to speak out against it.