In 1600 he entered the University of Leiden, where he studied theology under Jacobus Arminius, whose teaching he followed. In 1610, the year in which the Arminians presented the famous Remonstrance to the states of Holland, he became pastor at Bleyswick, a small village near Rotterdam; in the following year he advocated the cause of the Remonstrants at the Hague conference.
In 1612 he succeeded Franz Gomarus as professor of theology at Leiden, an appointment which awakened the bitter enmity of the Calvinists, and, on account of the influence lent by it to the spread of Arminian opinions, was doubtless an ultimate cause of the meeting of the Synod of Dort in 1618.
Episcopius was chosen as the spokesman of the thirteen representatives of the Remonstrants before the synod; but he was refused a hearing when he would not submit to the Synod's order of discussion -- which was for him to first present scriptural arguments for the Remonstrants' opinions. At the end of the Synod's sittings in 1619, Episcopius and the other twelve Arminian representatives were deprived of their offices and expelled from the country.
Episcopius retired to Antwerp and ultimately to France, where he lived partly at Paris, partly at Rouen. He devoted most of his time to writings in support of the Arminian cause; but the attempt of Luke Wadding to convert him to Catholicism involved him also in a controversy. After the death (1625) of Maurice, prince of Orange, the violence of the Arminian controversy began to abate, and Episcopius was permitted in 1626 to return to his own country. He was appointed preacher at the Remonstrant church in Rotterdam and afterwards rector of the Remonstrant college in Amsterdam, where he died.
Episcopius may be regarded as in great part the theological founder of Arminianism, since he developed and systematized the principles tentatively enunciated by Arminius. Besides opposing at all points the peculiar doctrines of Calvinism, Episcopius protested against the tendency of Calvinists to lay so much stress on abstract dogma, and argued that Christianity was practical rather than theoretical -- not so much a system of intellectual belief as a moral power and that an orthodox faith did not necessarily imply the knowledge of and assent to a system of doctrine which included the whole range of Christian truth, but only the knowledge and acceptance of so much of Christianity as was necessary to effect a real change on the heart and life.
The principal works of Episcopius are his Confessio declaratio sententiae pastorum gui in foederato Beiglo Remonstrantes vocantur super praecipuis artscuf is religionis Christianae (1621), his Apologia per confessione (1629), his Verus theologus remonstrans, and his uncompleted work Institutiones theoloricae. A life of Episcorius was written by Philipp van Limborch, and one was also prefixed by his successor, Etienne de Courcelles (Curcellaeus) (1586-1659), to an edition of his collected works published in 2 vols. (1650-1665). See also article in Herzog-Hauck, Realencyklopädie.