The Apostle Paul shows the church who they were and who they had become. He had to ordain elders but puts the emphasis on the children of God behaving themselves in subjection showing meekness to all men (through Titus.) Sometimes men think they are exempt from the laws of men..being "a cut above" them in the church. he would have them look in the mirror and not forget how they got to where they are and do it with all humility! He becomes bold giving us the words of our text.
Undeserved: Paul is very personal employing the personal pronoun "we were" in verse 3 and says we are the ones saved by grace and treat the world in kindness. We understand those things he speaks of are part of our old man and those which we have to struggle against ourselves. We are not "a cut above" the world. But it is utterly amazing that we are the children of God! Recipients of the kindness and the mercy of God Himself! It is an apiphany and appears to us! In Christ it became plain..the washing of regeneration by the Holy Ghost! As it was with Nicodemous "a light went on" and we were touched in our heart to come to knowledge of our salvation!
Gracious: We too were in the darkness and did not know the light until it shined in the darkness! Our Lord's broken body and shed blood...His own Son and the cross of Calvary! Redemption! We can then look back and see that we were no better than the world around us.
Effective: Then we can move about in this world living thankful DAILY for what God has done in our life! All loss for the knowledge of Christ my Lord! Who are we that God has set His love and His kindness upon us whereby we come to knowledge (know Him) and whereby we come to believe and take hold of Christ and what God has done for us!
"Amazing grace how sweet the sound that saved a WRETCH like you and me..."