Lawrence was brought up as a Puritan, and educated at Queens' College, Cambridge and then Emmanuel College, Cambridge, where he became an MA in 1627. He was a Huntingdonshire landowner who leased out grazing land to his distant relation Oliver Cromwell in the early 1630s. In the late 1630s Lawrence went to live in Holland where he felt freer to practice his form of Christianity, and remained there for most of the Civil War period. He published three religious books, "Of our Communion and Warre with Angels", and on the doctrine of baptism.
He entered Parliament in 1646 to fill a vacancy as Member for Westmorland. He was appointed a commissioner of Plantations in 1648 and commissioner for Ireland in 1652. In 1653 he was nominated a member of the Barebones Parliament, representing Hertfordshire.
He played no further part in public life after the Restoration, and died in 1664. John Milton's sonnet "Lawrence! of virtuous father virtuous son" was addressed to his eldest son; his younger son John emigrated first to Barbados, then Jamaica where he founded a wealthy dynasty of plantation owners.