The Lord introduces the reason with the little word “for.” He explains, “I have not found your works complete in the sight of my God.” Christ the judge has inspected the activities happening in his church in Sardis and found them to be of such insufficient quality that he cannot lay them before God. Jesus Christ knows that God will condemn what people approve (recall Revelation 3:1). The Christians of Sardis have work to do to improve, complete, fill up their deeds to meet God’s approval.
2 Wake up, and strengthen what remains and is about to die, for I have not found your works complete in the sight of my God.