Regarding the hadith "Kullu bid^atin Dalalah" "كل بدعة ضلالة وكل ضلالة في النار" , Imam an-Nawawiy and Ibn Hajar said this hadith means "Most innovations are innovations of misguidance" same as hadith "Kullu ^aynin zanyah" means: "Most people are guilty of the forbidden look."
That's why our Master Omar when he united Muslims in Taraweeh congregation, he said: "Ni^matul-Bid^atu Hadhihi".
Although most innovations are innovations of misguidance, there are numerous examples of Religiously acceptable innovations. During the Caliphate of ^Umar Ibnul Khattab, ^Umar initiated the gathering of people in Ramadan to pray the Tarawih Prayer in congregation. When he saw the people performing this prayer in congregation he said:
نِعْمَت البِدعَةُ هَذِه"ِ"
"What a good bid^ah (innovation) that is!"
The high status of ^Umar Ibnul Khattab is known, thus it is important to point out ^Umar used the explicit term البِدعَةُ "innovation" in his praise. If all innovations were misguided--as some claim--^Umar would not have innovated this practice, nor expressed this praise, yet both al-Bukhariyy and Muslim related this incident.
During the era of the followers of the Companions of the Prophet, another praise-worthy innovation took place. Initially, letters like the ba, ta, tha, and ya, did not have dots above or below them. This practice of distinguishing between the letters by using this notation began after the time of the Prophet. And there are many other innovations that have been innovated and accepted in Islam.
So let one be careful and open minded and bewarned of wahhabis whom are close minded. Wahhabis are a tiny sect that strayed from Jama^ah. We sunnis follow our four imams, wahhabis say "Following (Taqleed) the imams is Shirk". See their book called Deen al-Khalis page 140.
We ask Allah to protect us from extremism and fanaticism, and to keep us steadfast on the path of the majority of the Ummah of Ahlus-Sunnah wal Jama^ah, ameen.