In every thing give thanks: for this is the will of God in Christ Jesus concerning you. In everything - even what seems adverse; for nothing is really so (cf. Romans 8:28; Ephesians 5:20.) So Christ (Matthew 15:36; Matthew 26:27; Luke 10:21; John 11:41).
This - that ye should "in every thing give thanks," "is the will of God in Christ Jesus (the Mediator in whom that will is revealed: cf. Philippians 3:14) concerning [toward: eis (G1519)] you." God's will is the believer's law. Put commas after each of the three precepts (1 Thessalonians 5:16-18), making "this" refer to all three.