“A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit.”
Matthew 7:18 — Greek Interlinear
Church Fathers on Matthew 7:18
The Lord had before commanded His Apostles, that they should not do their alms, prayers, and fastings before men, as the hypocrites; and that they might know that all these things may be done in hypocrisy, He speaks saying, 'Take heed of false prophets.'
When the Lord had said that there were few that find the strait gate and narrow way, that heretics, who often commend themselves because of the smallness of their numbers, might not here intrude themselves, He straightway subjoins, 'Take heed of false prophets.'
Having taught that the gate is strait, because there are many that pervert the way that leads to it, He proceeds, 'Take heed of false prophets.' In the which that they might be the more careful, He reminds them of the things that were done among their fathers, calling them 'false prophets;' for even in that day the like things fell out.