1 Corinthians 1:9

πιστός. God is faithful, i.e. to be depended upon. He will not fail on His part, if we are but true to ourselves and to Him.

δι' οὗ. This use of διὰ in reference to the causa principalis is unusual. See Winer, Gr. Gram. Pt III. § 47.

κοινωνίαν. The important word here rendered fellowship in A.V. has unfortunately different renderings in that Version. Sometimes, as in ch. 1 Corinthians 10:16 (where see note), it is rendered communion; and in 2 Corinthians 6:14, where it is thus rendered, another word is rendered fellowship. In 2 Corinthians 9:13, it is rendered distribution. Its usual signification would appear to be the sharing together, joint participation as common possessors of anything. But it is impossible to go so far as Cremer in his Lexicon of the N. T. and assert that it never has the active sense of communication, in the face of such passages as Romans 15:26 (where it is rendered contribution); 2 Corinthians 9:13. Here it refers to the life which by means of faith is common to the believer and his Lord. Cf. Galatians 2:20.