When making choices as to where to draw the boundaries around the Catholic faith, Catholics decided that laughter had been decisively tainted by the fact that it had been so popular among the gnostics. Christians of all varieties would henceforth generally treat laughter with extreme suspicion, particularly anywhere near the liturgy, but with a far wider reference than that. One Syrian word for a monk is abila, ‘mourner’. One of several Christian spiritual writers who sought to borrow respectability for their works by placing them under the name of the much-honoured fourth-century Syrian ascetic Ephrem insisted that Jesus had cried, but had never laughed; so ‘laughter is the beginning of the destruction of the soul’.
– Diarmaid MacCulloch, Silence: A Christian History (2013)