17. Therefore if any man be in Christ. The phrase to “be in Christ,” evidently means to be united to Christ by faith; or to be in him as the branch is in the vine—that is, so united to the vine, or so in it, as to derive all its nourishment and support from it, and to be sustained entirely by it. John 15:2, “Every branch in me.” ver. 4, “Abide in me, and I in you”. “The branch cannot bear fruit of itself except it abide in the vine; no more can ye except ye abide in me.” See also ver. 5–7, see Note