The wood of a grape branch by itself is useless (Eze 15:2-5) and can only be burned. So it is with those who do not remain in Christ (Matt 13:40-43). “Those that abide not in Christ, though they may flourish awhile in a plausible, at least a passable profession, yet in a little time wither and come to nothing.” (Job 8:11-13) (Matthew Henry)

Ezekiel 15:2-5  “Son of man, how is the wood of a vine better than that of a branch on any of the trees in the forest?  Is wood ever taken from it to make anything useful? Do they make pegs from it to hang things on?  And after it is thrown on the fire as fuel and the fire burns both ends and chars the middle, is it then useful for anything?  If it was not useful for anything when it was whole, how much less can it be made into something useful when the fire has burned it and it is charred?

Matthew 13:40-43  “As the weeds are pulled up and burned in the fire, so it will be at the end of the age.  The Son of Man will send out his angels, and they will weed out of his kingdom everything that causes sin and all who do evil.  They will throw them into the fiery furnace, where there will be weeping and gnashing of teeth.  Then the righteous will shine like the sun in the kingdom of their Father. He who has ears, let him hear.

Job 8:11-13  Can papyrus grow tall where there is no marsh? Can reeds thrive without water?  While still growing and uncut, they wither more quickly than grass.  Such is the destiny of all who forget God; so perishes the hope of the godless.

These are very strong words which emphasize the necessity to remain in Christ if fruitfulness is to continue. Strachan notes, “Unfruitfulness alone separates men from Christ and His Church. The Church without a sense of mission is no church.”