What does John 15:6 mean?
Earlier in this passage, Jesus distinguished between branches "in" a vine and branches which "abide in" the vine. Merely being close to the source of life is not enough; neither is being intertwined with other branches. Only branches truly connected to the source of life—the vine—will bear fruit. A good vinedresser cuts out those dead, fruitless branches and destroys them. The analogy Jesus presents here is not about loss of salvation, which is impossible. Rather, His message is about those who "put on" an appearance of faith, but are disconnected from the True Vine that gives eternal life.For the purposes of this statement, that is what Jesus means by those who "abide in [Him]." Bearing true spiritual fruit is only possible through the power of Christ (John 15:4–5). That fruit, like any other good works or holiness, is always presented as evidence of salvation, never as a requirement for it.
The pruning and destruction Jesus refers to here echoes a statement made in Matthew 7:21–23. There, Jesus likewise pointed out that putting on an appearance of faith is not the same as being born again.