Baillie was born in the
Saltmarket,
Glasgow, the eldest son of James Baillie, a merchant and
burgess of Glasgow, and his wife, Helen Gibson. He was educated at the
High School of Glasgow and the
University of Glasgow, graduating with an M.A. in 1620. He was licensed by Archbishop
James Law and became a regent of Philosophy in the University, and tutor to the son of
Alexander Montgomery, 6th Earl of Eglinton. He was ordained to
Kilwinning on 25 May 1631 and admitted burgess of Glasgow 6 July 1631. In 1638 he represented the Presbytery of
Irvine at the Glasgow Assembly, when
Presbyterianism was re-established in Scotland. In 1639 he accompanied Lord General
Alexander Leslie and the Scottish army as chaplain to Lord Eglinton's Regiment during the
Bishops' Wars. In 1640 he was appointed by the Covenanters to draw up an accusation against
Archbishop Laud. On 11 August 1642 he was translated to the Tron Kirk in Glasgow. In the same year, Baillie was made
Professor of Divinity at the University of Glasgow, holding the chair jointly with
David Dickson. In 1643 he was selected as one of the five Scottish clergymen who were sent to the
Westminster Assembly. In January 1647 he presented the completed
Confession of Faith and a version of the Psalms in metre to the
General Assembly of the Church of Scotland. In 1649, Baillie was one of the commissioners sent to Holland for the purpose of inviting
Charles II to Scotland, and of settling the terms of his admission to the government. He continued to take an interest in religious controversies during the
Interregnum, but was not active politically. In 1661 he was made
Principal of the University of Glasgow in place of
Patrick Gillespie. He died the following year, in August 1662. ==Liturgical controversies==