"Renewed" is another word which describes salvation.  It means "to make new again, to revive, reawaken ... new, different."  

2 Corinthians 4:16 in the Amplified Bible says that our inner self ... our inward man ... is progressively renewed day after day.  

Colossians 3:10 tells us that the renewal of spiritual power of the new inward man is being renewed unto knowledge ... (the knowledge of God.)  

The Amplified Bible says it this way: "And have clothed yourself with the new [spiritual self] which is ever in the process of being renewed and remolded into fuller and more perfect knowledge, after the image [likeness] of Him Who created it."  

Ephesians 4:23 ... "Be constantly renewed in the spirit of your mind --- having a fresh mental and spiritual attitude."  This talks about the true knowledge of Christ.  The spirit of the mind is under the controlling power of the indwelling Holy Spirit Who directs  your mind's energies toward God, enjoying fellowship with the Father and with Jesus Christ, thus fulfilling God's will.  

 Reverend Robert W. & Mary C. Butler