In what amounts to a postscript to his sermon, the author takes care to specify particular ways in which this true and living faith expresses and evidences itself. As elsewhere in the Bible, the believer is not left to work out the ethical implications of faith in Christ; the particular obedience required is carefully defined. Pride of place goes to brotherly love (13:1–3), a costly virtue by which these believers have already distinguished themselves, especially in regard to prisoners (Heb. 6:10; 10:33–34). Abraham is again invoked as an example, this time of hospitality (Gen. 18:1–16; cf. 1 Pet. 4:9) and of the blessing that attends the gracious host. Christian sympathy and fellow feeling (cf. Rom. 14:15; 1 Cor. 12:26) will not be satisfied with the simpler forms of charity but will ext…