Hazrat Abu Ayyub Sakhtiani observes that the more an innovator struggles, the farther he gets from Allah.
Hazrat Sufyan Thauri remarks that, compared to sinning, Iblis (Satan) likes innovation more, because considering a sin to be a sin one can repent for committing it, but innovation is such a deviation that one does not repent for it, for it is not considered a sin. He also remarks that Allah Most High will not give any benefit to the man who heard things of knowledge from an innovator, and one who shook hands with an innovator, who caused distress to Islam.
A man came to the presence of Hazrat Abullah ibn Umar and said that, so and so had sent his compliments to you. Ibn Umar said: "I have heard that he has invented a new thing (bid'ah). If it be so that he is enmeshed in innovation, do not say, "on you also be peace" on my behalf in response to his compliment." (Mishkat: vol. ii, p.23)
Sa'eed bin Kurayz reports that Sulaiman Taimi fell ill. During his illness he began to cry too much. At last he was asked: "Why do you cry? Are you so perplexed by death"? He said: "No. But the thing is this, that one day I happened to pass by an innovator who was a denier of fate and used to call the created beings masters of free will, and (once) I had saluted him. Now I am terribly afraid that my Lord may not take me to task for it.”