Hello Golden!
Then the LORD said to me, "The prophets are prophesying lies in my name. I have not sent them or appointed them or spoken to them. They are prophesying to you false visions, divinations, idolatries and the delusions of their own minds" (Jeremiah 14:14).
I believe you have the answer to many of your questions in the above scripture. Why do we need to confront false prophecy? - because it's lies being spoken in God's name- blasphemy. How can we combat lies? - with righteousness and truth.
The 'Pharisaical Spirit' and Cessationism are growing as a reactionary process because those who prophecy lies in God's name are being given free and unhindered reign to abuse God's sheep.
For example speakers who claim special revelation but share a false gospel, preaching a false Jesus and operating in a false spirit (2 Corinthians 11:4) should be treated as we treat Mormons and Muslims. They should not be encouraged, supported or given the benefit of the doubt. If they persist they should be marked and avoided and so should those who support them. Truth and lies cannot co-exist. Truth is something we should regard as very precious.
There is no solution in ignoring the false prophets in the body because we already know that they are evil men and impostors who will grow worse and worse if they are not tackled (2 Timothy 3:13).
God Bless