What is the Shar'i (Islamic legal) opinion on dealing with the Jama'at al-Da'wah wa al-Tabligh (the Tablighi Jama'at), and is going out with them and applying the Six Qualities considered a bid'ah (innovation), especially given the noticeable turnout of people towards them and the guidance of many at their hands?

The ruling on going out with Jama'at al-Tabligh has been clarified in a previous fatwa (definition). As for the "Six Qualities," they are for training beginners in the fundamentals of religion, and they include: certainty in the word of Tawhid (definition) (Oneness of God), prayer with humility, knowledge accompanied by remembrance of God, showing respect to Muslims, purifying and dedicating intentions solely for God, and inviting to God and going forth in His path. These qualities are among the fundamentals of religion.