Rabbi Nachman of Breslov stated that “someone who has faith is constantly calm,” and proved it from the Torah.[1]
On the verse (Devarim 1:12) “How can I bear your trouble, your burden, and your strife all by myself?” Rashi comment on the words your trouble stating, “This teaches that they [the Israelites] were heretics.”
He went on to elaborate: “the heretic is under content emotional stress in contrast to the man of faith who is always emotionally at ease and satisfied in all that he has.”
[1] Otzar Pitgamim Vesichot, Vol. 2, Pg. 20
