Summary: As the consummation of the Age nears, the infiltration of evil into the churches will become more pronounced, requiring awareness and resistance from the faithful.
“Understand this, that in the last days there will come times of difficulty. For people will be lovers of self, lovers of money, proud, arrogant, abusive, disobedient to their parents, ungrateful, unholy, heartless, unappeasable, slanderous, without self-control, brutal, not loving good, treacherous, reckless, swollen with conceit, lovers of pleasure rather than lovers of God, having the appearance of godliness, but denying its power. Avoid such people. For among them are those who creep into households and capture weak women, burdened with sins and led astray by various passions, always learning and never able to arrive at a knowledge of the truth. Just as Jannes and Jambres opposed Moses, so these men also oppose the truth, men corrupted in mind and disqualified regarding the faith. But they will not get very far, for their folly will be plain to all, as was that of those two men.” 
You may be certain that difficult days are coming. When the Apostle wrote, “Understand this,” he was stressing that which was definite. Timothy, and thus all Christians, needs to learn that tough times are coming. It is the responsibility of the pastor to warn of what is coming; and those who hear are responsible to echo that warning. Paul doesn’t merely sound out a vague warning, he is quite specific about what the future holds for the Faith.
In order to have a thorough grasp of Paul’s prophecy concerning the last days, we will benefit from review of other instance of similar warnings from the Apostle. In an earlier missive, Paul wrote, “The Spirit expressly says that in later times some will depart from the faith by devoting themselves to deceitful spirits and teachings of demons, through the insincerity of liars whose consciences are seared” [1 TIMOTHY 4:1, 2]. Paul is clearly warning that the last days are to be marked by demonic assault of the Faith and infiltration of the Faith by evil people. In this latter letter, the Apostle will focus on the individuals controlled by the demonic powers.
This insinuation of evil into the worship of the Living God is not a new phenomenon, this intrusion by those who act wickedly has continued as long as mankind has worshipped the LORD God. God, through Jeremiah, exposed this evil before the House of David fell in the last days of the Judean Kingdom. God said, “The prophets are prophesying lies in my name. I did not send them, nor did I command them or speak to them. They are prophesying to you a lying vision, worthless divination, and the deceit of their own minds” [JEREMIAH 14:14].
In a later chapter, God again exposes the evil of the religious leaders,
“In the prophets of Jerusalem
I have seen a horrible thing:
they commit adultery and walk in lies;
they strengthen the hands of evildoers,
so that no one turns from his evil;
all of them have become like Sodom to me,
and its inhabitants like Gomorrah.”
God exposed what was happening when He said, “Thus says the LORD of hosts: ‘Do not listen to the words of the prophets who prophesy to you, filling you with vain hopes. They speak visions of their own minds, not from the mouth of the LORD. They say continually to those who despise the word of the LORD, “It shall be well with you”; and to everyone who stubbornly follows his own heart, they say, “No disaster shall come upon you”’” [JEREMIAH 23:16, 17].