Seagrave figures in the DNB as a Whitefield-following evangelical who either left the established church or took a strongly evangelical line within it. In this capacity he is relevant to midcentury poetry as a writer and editor of evangelical hymns. But the ESTC also attributes a (pre-conversion?) Whig panegyric poem to him. He was also very active in writing polemical divinity with a heavy emphasis on the "protestantism" of evangelicals.