“A perpetual fire shall be lit on the altar; it may not be extinguished.” (Leviticus 6:6)
According to the Talmud (Zevachim 91b) extinguishing even a single coal on the altar is a transgression.
When we’re young, we have a healthy, enthusiastic and pure simple faith. We should never become jaded with cynicism as we get older and allow our youthful joy and fire to be dampened.