"So also when He says, The good Shepherd gives His life for the sheep, He is not the only one who has done such a deed; and yet if those who have done so are His members, He only Himself was the doer of it. For He was able to do so without them, but whence had they the power apart from Him, who Himself had said, Without me you can do nothing? But from the same source we can show what others also have done, for the apostle John himself, who preached the very gospel you have been hearing, has said in his epistle, Just as Christ laid down His life for us, so ought we also to lay down our lives for the brethren." (St Agostine)