This is an old proverb, which means: good intentions lead to bad things.
The earliest version is Virgil's Latin poetry collection "Aeneid": the descent to hell is easy.
More people believe that this sentence originated from the West I met a French abbot, Saint Bernard of Clairvaux (1090-1153), and then printed it in the book "Correspondence: Lettres d'Amitié Spirituelle" by St Francis de Sales: hell is full of good wishes or desires .
Various similar versions appeared later, until James Boswell used this sentence (1791) in his influential work The Life of Samuel Johnson LL.D.: Sir Hell is paved with good intentions. And this sentence actually comes from John Ray's book (1670): A Collection of English Proverbs.
Nowadays, Bernard of Clairvaux or Samuel Johnson are generally regarded as the authors of this famous saying.