15:4 Abide in me. The verb “abide” is the same in the Greek as “continue” or “remain,” and is used no less than twelve times in John 15:4-16. The same word is used in John 8:31 when Jesus said those who “continue in my word” are “my disciples indeed.” See also John 15:7. Thus, abiding in Christ is not some mystical concept but simply adhering strictly to the words of Christ as found in the Scriptures, guarding them as true and authoritative in every respect, and seeking to obey them by God’s help.
15:4 cannot bear fruit. There are various kinds of “fruit” which Christians should produce. There is the nine-fold “fruit of the Spirit” (Galatians 5:22-23), manifest in gracious and consistent Christian character, as well as “the fruits of righteousness” (Philippians 1:11; Hebrews 12:11). Ephesians 5:9 says that “the fruit of the Spirit is in all goodness and righteousness and truth,” and all of this will produce fruit in the form of others won to Christ. For example, Paul expressed to the people in Rome his desire to “have some fruit among you also, even as among other Gentiles” (Romans 1:13).
15:5 abideth in me. Certain outward evidences can be observed when one is truly “continuing” in Christ. “He that saith he abideth in Him ought himself also so to walk, even as He walked” (I John 2:6). “Whosoever abideth in Him sinneth not” (I John 3:6). “If ye abide in me, and my words abide in you, ye shall ask what ye will, and it shall be done unto you” (John 15:7). There would be exceptions, of course, for no one is perfect, but these attributes can and should be generally evident in those who are really in Christ.
15:5 can. Here the word “can” here is the Greek dunamai, indicating “have the power to.”