When he left Ephesus for Macedonia Paul left Timothy behind with authority to oversee the church there (1Timothy 1:3). So, Timothy was left to confront certain believers who had a tendency to teach in a manner contrary to the way of Paul (1Timothy 1:3). Later Paul met with the leaders of the churches of Asia, including Ephesus, when he was making his final voyage to Jerusalem. He told the elders to really consider the positions they had been given in the church by the Holy Spirit, and feed those entrusted to them (Acts 20:29). Paul warned that after he left, men would enter the church who would have no love for the brethren. Rather, they would scatter the church, abuse the brethren and become a burden to them (Acts 20:30). Even men of their own number would arise to teach false doctrines in order to gather a following after themselves (Acts 20:30).
Originally, the church at Ephesus was successful in their battle against these evil men, who sought either to destroy the church, or as false apostles, to gain a following after themselves (Revelation 2:2). Nevertheless, according to Acts 20:29-30, all this would change, once Paul left. Years later, after Paul was imprisoned in Rome, he would write to Timothy, saying “all they which are in Asia” (including the church at Ephesus) had turned away from him (2Timothy 1:15). It seems they were opposed to being associated with Paul, the Roman prisoner, because Paul made a special point in saying Onesiphorus was unashamed of him and even sought Paul out, while Onesiphorus was in Rome, in order to help him. The point is, there is a sense of greater corruption going on in the church at Ephesus, after the time of John’s writing the Apocalypse.
Additionally, Paul warned Timothy (and, therefore, the church at Ephesus) against being occupied with Jewish myths (1Timothy 1:4). Jewish myths were fictional stories told to support a supposed truth or make light of a supposed error. The myth of Lazarus and the Rich man in Luke 16:19-31 is such a story, but the Lord changed parts of it and added to it, in order to establish his own argument against the Sadducees. Jesus’ argument in Luke 16 shows that his enemies wouldn’t repent, even if one rose from the dead. That myth (minus Jesus’ additions) was probably used by Sadducees to deny the resurrection, which the Pharisees proclaimed as true. Such myths only generate controversy. They don’t prove anything and should be avoided.
Moreover, Timothy was warned against being occupied with endless genealogies (1Timothy 1:4), probably with the intent to establish pedigree for someone wishing to be recognized as a leader on the ground of his Jewish descent. The problem was that many of the genealogical records were corrupted as seen in this excerpt from the Babylonian Talmud:
Rami, the son of Rabbi Judah, said: Since the day that the Book of Genealogies was hidden, (probably meaning corrupted or destroyed) strength of the Sages has been impaired and the light of their eyes has been dimmed. Mar Zutra said, Between ‘Azel’ and ‘Azel’ (i.e. between 1Chronicles 8:38 – “And Azel had six sons…” and 1Chronicles 9:44 – “And Azel had six sons…”) they were laden with four hundred camels of exegetical interpretations! (meaning voluminous commentary). [Babylonian Talmud: Pesachim 62b – parenthesis mine]
The point is that at least many of the genealogical records weren’t clear or couldn’t be verified as authentic. These, too, when offered as evidence that God had chosen the bearer to be a leader and a teacher only generated controversy. Paul claimed such records couldn’t be used as evidence of anything.
Ultimately, however, the church embraced these false teachers, who claimed to be Apostles, and the church descended into believing controversial doctrines that no one could prove correct.
“The end at which our warning aims is charity, based on purity of heart, on a good conscience and a sincere faith. There are some who have missed this mark, branching off into vain speculations; who now claim to be expounding the law, without understanding the meaning of their own words, or the subject on which they pronounce so positively. (1 Timothy 1:5-7 – Knox translation of the Vulgate – emphasis mine)
Although Paul’s warnings were intended to bear the fruit of love, founded upon a clean heart and a good conscience within the church, ultimately the church erred from its sincere faith, turning away from Christ as the Head of the church in order to follow another “head” who preached controversial doctrines of uncertain truth.