Let us serve God…

  Acceptably. 12:28

  Reverently. cf. 1Tim 2:9

  Fearfully. Cf. Acts 2:5; Heb 5:7

  Praise Continually. 13:15; 1Pet 2:9

  Thankfully. 1Thess 5:18

  Prayerfully. 13:18; 1Thess 5:17.

See overview of Hebrews here.