He was born in Cornwall, where he first heard of the Methodists in 1742. He heard them preach in 1744, was converted and became a local preacher. He entered the itinerancy in 1749 (not 1742, as stated by various sources) and continued until his death. He was stationed in Ireland from 1751 to 1756, and most of his subsequent circuits were in Bristoland Cornwall. While John Wesley clearly valued his services, the evidence for his life and ministry is fragmentary. The best source is Gilbert's own 'Short Account of God's Dealings with a Sinner' (ms in the Methodist Archives, Manchester). He has often been wrongly associated with the Gilbert family of Antigua.