Leaven – Spiritual
Where leaven is the translation in the New Testament of the King James Version it may refer to the physical usage at times, but it usually will have a spiritual meaning also.
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, Matt. 16:12.
And he charged them, saying, Take heed, beware of the leaven of the Pharisees, and of the leaven of Herod, Mark 8:15.
In the mean time, when there were gathered together an innumerable multitude of people, insomuch that they trode one upon another, he began to say unto his disciples first of all, Beware ye of the leaven of the Pharisees, which is hypocrisy, Luke 12:1.
From the first two Scriptures we learn that there are three groups of people that Yahshua tells His disciples to watch out for: the Pharisees, the Sadducees and the Herodians.
Luke 12:1 speaks to the leaven of the Pharisees as the religious hypocrisy exhibited in their external ceremonialism. The leaven of the Sadducees was their disbelief in an afterlife and the coming of the Messiah. The leaven of the Herodians dealt with a political family who opposed Yahshua.
Matt. 16:12 specifies that the leaven of the Pharisees and Sadducees is their doctrine while Luke 12:1 says the same thing about the Pharisees.
Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth, 1 Cor. 5:8.
In the last two Scriptures there are three words of interest: hypocrisy, malice and wickedness. Through examination we will find that they are related to unhealthy attitudes.
Hypocrisy is a translation of the Greek 'Hupokrisis' (Strong's #5272), whose root word means to play a part, deceitful pretending.
Malice is a translation of the Greek 'Kakia' (Strong's #2549), whose root word means to have ill will, desire to injure.
Wickedness comes from the Greek 'Poneria' (Strong's 4189), whose root word means to be hurtful or evil.
1 Cor. 5:8 then says that one must avoid those activities which center on deceiving others or which have evil purposes directed towards others.
Sincerity is a translation of the Greek 'Eilikrineia' (Strong's #1505), whose root word means to be genuine.
Truth comes from the Greek 'Aletheia' (Strong's #225), whose root words mean not concealing.
Our actions then, at the time of the Feast of Unleavened Bread, should be genuinely truthful.