At least 3 reasons why Sufis are dangerous:

We go times of the following assumption: All Muslims want to paradise and want to live this way so that Allah is happy with them. Therefore, the entire action (ie the action for a "good" indeed), but also the entire non-action (the action that are of a sin capacity) designed to Allah with a Muslim is happy.

If we in the Quran Allah says: "Today I completed your religion you (so that nothing more that is missing) and my grace to you complete and admit you to the Islam faith chosen." (Surah 5, verse 3), then believe the Muslims that the religion is not to be 99.8% and 99.9% do not complete, but at 100%. Nothing is more pure.

Nevertheless, there are things that at the time when the verse was not revealed in Islam has been made, but afterwards were introduced and one wonders why is this so?

On the one hand, one can say that among those who are who do not know that it is not the origin belongs to.

How to deal best with them?

Very simple. If they say their actions are Muslim and others say they are not, then you must do what Allah asks in the Quran: "O, ye who believe, obey Allah and obey the Messenger and those among you command possess. And if you argue about something, it brings it to Allah and His Messenger, if ye believe in Allah and the Last Day. That is the best and is most likely a good outcome. "(Sura 4, verse 59)

So you need to see what was originally in religion has been done. And either we find the action or not. So the plot continues, or it must be

But then there are people who make it, even though they know that it is not the origin belongs to.

What does this mean?

That means nothing other than the demonstration of three possibilities about the nature of Allah:

1. Allah is forgetful. Because, as he "completes" said, he had forgotten that there was still something inside had what he later revealed to Muslims, then why the innovations practiced as Islamic acts. Or

2. Allah lies. Indeed, Allah is not forgetful but has intentionally lied when he "completes" said. Or

3. Allah deceives the people. Indeed, Allah is not forgetful and does not lie, but just wanted to be the first generations of Muslims cheat by giving them something for 100% sold, but still not "completed" was because the innovations were missing.

Apart from the above mentioned things that mean the conscious pursuit of new things in religion is nothing other than:

For which side you decide?

For Allah, or for someone who says, at least on the same level as Allah, and are believed to possess the authority to say what is right and what is wrong?