Dan,
Jesus warned about the "leaven", defined as "deception" promoted by the mainstream religions of the world at that time, "Who Professed to know God" and told me to "Take Heed" I am not deceived by them. Before God Sent Jesus, HE sent Jeremiah to warn about the same deception promoted by the mainstream preachers of his time, "who professed to know God".
Jer. 23:
16 Thus saith the LORD of hosts, Hearken not unto the words of the prophets that prophesy unto you: they make you vain: they speak a vision of their own heart, and not out of the mouth of the LORD. 17 They say still unto them that despise me, The LORD hath said, Ye shall have peace; and they say unto every one that walketh after the imagination of his own heart, No evil shall come upon you.
So because I believe all that is written in the Law and Prophets, I am careful not to just believe anyone who calls Jesus Lord, Lord, but to prove the teaching based on what is actually written in Scriptures. In doing so, I have discovered many "leavens" promoted by the religions of this world God placed me in.
For instance, the very popular but false teaching that Peter is calling God's Laws, Statutes and commandments, "a burden or Yoke" in Acts 15.
The mainstream preachers of that time, the Pharisees, were certainly attempting to place a Yoke on the necks of the Disciples that they nor their fathers could bear. Jesus spoke of this "Burden" when HE instructed the multitudes and the Disciples to listen to Moses, "when he was read in the Temple on God's Holy Sabbath Days". (Keep in mind this was the only way at that time that they could hear Moses)
Consider what the Jesus "of the Bible" said about the mainstream preachers of that time,
who said they promoted the Law of Moses, but did not.
Matt. 23:
1 Then spake Jesus to the multitude, and to his disciples, 2 Saying, The scribes and the Pharisees sit in Moses' seat: 3 All therefore whatsoever they bid you observe, that observe and do; but do not ye after their works: "for they say", and do not.
4 For they (Pharisees, not God) bind heavy burdens and grievous to be borne, and lay them on men's shoulders; but they themselves will not move them with one of their fingers.
Peter was there when Jesus taught this. To promote the philosophy that Peter forgot, or rejected His Lord's teaching in Act's 15 is foolishness, and when a man considers all that is written, it is a deception.
Peter wanted to keep the Gentiles away from the traditions of men that Jesus said the Pharisees taught for doctrines, when they claimed to believe Moses, and directed them toward the actual Word's of God through Moses. It's right there in the Scriptures, all a man needs is belief.
14 Simeon hath declared how God at the first did visit the Gentiles, to take out of them a people for his name.
15 And to this agree the words of the prophets; as it is written,
16 After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up:
17That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is called, saith the Lord, who doeth all these things.
18 Known unto God are all his works from the beginning of the world.
19 Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God:
20 But that we write unto them, that they abstain from pollutions of idols, (Law of Moses) and from fornication, (Law of Moses) and from things strangled, (Law of Moses) and from blood. (Law of Moses)
21 For Moses of old time hath in every city "them that preach him", (Pharisees and Scribes) being read in the synagogues every sabbath day. (Just don't do what they do because they "profess to know God" but reject His Commandments to promote their own religious traditions))
Peter and the Apostles directed the Gentiles to do the exact same thing that the Jesus "of the Bible" commanded of them.
This entire philosophy promoted by this world's religions God placed us in, that somehow God's Judgments, Laws and instruction in righteousness is the plague on mankind leading them astray, burdening men with blindness and ignorance, and are a Yoke of Bondage, Beggarly Elements and Rudiments of this world is certainly a popular philosophy dating back to Eve and the first mainstream preacher "of this world", who professed to know God, ever to be recorded. Consider the foundation of his philosophy.
Gen. 3:
4 And the serpent said unto the woman, Ye shall not surely die: (God Lied to you)
5 For God doth know that in the day ye eat thereof, (Reject the Commandment) "then" your eyes shall be opened, and ye shall be as gods, "knowing" good and evil.
The "Yoke/burden" that the mainstream preachers of that time were tempting God, by attempting to place them on the Gentiles was not God's Laws given to Moses. They "said" it was, but Jesus had already shown the Apostles that it wasn't.
This is just ONE of the "many Leavens" promoted by the "many" who come in Christ's Name, that Jesus warned about. I hope you might consider.