Gr. eidos, “external appearance,”“form,”“shape.”Eidos refers to the thing which is seen, not to the faculty of seeing (cf. Luke 9:29, “fashion”; John 5:37). We believe in the Lord without having seen Him. Until the time when we do see Him face to face our manner of life as Christians rests on our belief in the unseen. There are two worlds, the visible and the invisible, which would be one except for the entrance of sin. A person walks by sight when he is under the influence of the material things of time, but he walks by faith when he is under the influence of things eternal. The decisions of the unregenerate man are made, his conduct determined, by external appearances. But the Christian has so firm a conviction regarding the realities of the eternal world that he thinks and acts by faith, in the light of things visible only to the eye of faith (see on Matt. 6:24-34; 2 Cor. 4:18). Those who walk by sight instead of by faith thereby express doubt concerning the invisible realities and the promises of God. By faith the kingdom of God becomes a living reality, here and now. Faith comes by “hearing,” and “hearing by the word of God” (see on Rom. 10:17). See on Heb. 11:1, 6, 13, 27, 39.
By faith.
Paul’s confidence in the resurrection (vs. 6, 8) has faith for its basis (see on ch. 4:18). In this life the apostle walks by faith, as in the life to come he will walk by sight.