In 1840 he became a minister at the Dutch Reformed Church in Heemstede. In the same year he married Aleida van Foreest. In 1854 he moved to Utrecht where from 1874 till 1884 he was a professor in church history at the University of Utrecht.
His most famous work is Camera Obscura, which he wrote under the pseudonym Hildebrand during his student years. The first version appeared in 1839. In later years he kept adding stories to the work. Therefore, only in 1851, the final version was finished.
Beets died at the age of 88 in Utrecht of a brain haemorrhage.