the fruit bearing has nothing to do with salvation. Jesus is talking to his 11 disciples, they are all saved. this parable is not about losing your salvation because we are eternally secure, nothing can pluck us out of Christ's hand or the Father's hand. nothing can separate us from the love of Christ.
the parable is teaching that if we do not have complete continuous fellowship with Christ, spoken of abiding in him and he in us, then we will bear no fruit. what is gathered together is the carnal work, the wood hay and stubble which shall be burned, but if our works are precious stones gold and silver they shall remain.
the same can be understood when we look at Lot. he was out of fellowship with the Lord. he produced no lasting fruit all the while he was in Sodom. all he had was burned with that wicked city, yet he was saved yet so as by fire.
I hope this helps your understanding of this subject