How can Jesus have a different assessment about the health of the church of Sardis than people have?
People see the outside and form an evaluation on such externalities as church attendance, donations of money and time to church causes, living a Christian ethic. Christ looks at the heart and so penetrates to the deeper question of motive (see further 1 Samuel 16:7; Matthew 23:1–39).
1 Ecris à l'ange de l'Eglise de Sardes: Voici ce que dit celui qui a les sept esprits de Dieu et les sept étoiles: Je connais tes œuvres. Je sais que tu passes pour être vivant, et tu es mort.