The Sunnah is Nourishment For The Hearts – By Ibn Taymiyyah [rahimhullaah]
Shaikhul Islaam Ibn Taymiyyah [rahimahullaah] said:
The legislated divine law is nourishment for the hearts, so when the hearts are nourished with bidah, giving preference to the Sunnan does not remain in them; then [the affair] becomes like [the situation of a person] who nourishes himself with filth.
[Iqtidaa Siraat Al-Mustaqeem: 1/281. Slightly paraphrased]