Matthew 16:5-12

"And when his disciples were come to the other side, they had forgotten to take bread. (6) Then Jesus said unto them, Take heed and beware of the leaven of the Pharisees and of the Sadducees. (7) And they reasoned among themselves, saying, It is because we have taken no bread. (8) Which when Jesus perceived, he said unto them, O ye of little faith, why reason ye among yourselves, because ye have brought no bread? (9) Do ye not yet understand, neither remember the five loaves of the five thousand, and how many baskets ye took up? (10) Neither the seven loaves of the four thousand, and how many baskets ye took up? (11) How is it that ye do not understand that I spake it not to you concerning bread, that ye should beware of the leaven of the Pharisees and of the Sadducees? (12) Then understood they how that he bade them not beware of the leaven of bread, but of the doctrine of the Pharisees and of the Sadducees."

The caution the Lord gave to his disciples then; of a leaven in their doctrine, I venture to believe, was generally intended as a caution to all his disciples, in every age of the church. And never was there a period where the caution was more needful than now. Oh! what a leaven mixes in the present hour with the pure doctrines of Christ, and even in churches calling themselves Christian? Freewill, self-righteousness, improvements of grace, and conditional salvation with some, and the denial of the Holy Spirit's agency, with the work of regeneration, and the justifying righteousness of the Lord Jesus Christ with others, to say nothing of numberless other corruptions which have crept, in among men, to the great injury of the faith once delivered unto the saints, these too plainly prove that the precept of Christ, to beware of the leaven of deception and error in doctrine, is highly seasonable in the present day of the Church.