Romans 15:17

ἔχω οὖν. οὖν refers to the preceding statement of his mission—being in this relation to Christ Jesus and engaged on this work for Him, I am bold beyond what I should be if I were acting on my own account; shows how this statement justifies τολμ. ἔγραψα.

ἔχω καύχησιν = καυχῶμαι, emphasising the durative action.

ἐν Χρ. Ἰ. In my union with and service of Christ Jesus.

τὰ πρὸς τὸν θεόν. As regards my relation to GOD: accus. of ref. Blass, p. 94; cf. Hebrews 2:17.