This chapter explores perceptions of the spiritual life cycle in Protestant England. It examines how the rhetoric and language of the human life cycle and reproduction was deployed to describe personal religious growth and considers the complex relationship between biological and spiritual conceptions of age in the post-Reformation context. Drawing on the biblical idea of casting off the old man and taking on the new, godly Protestant piety increasingly placed emphasis on experiences of conversion, regeneration and rebirth. At the same time the reformers were eager to resist the perennial charge that Protestantism was a ‘new’ religion and to prove that it had ancient apostolic roots. The essay teases out this paradox. It pays particular attention to the Restoration divine Ralph Venning’s Christs School (posthumously published in 1675), which described the four classes of Christians he had encountered in the course of his ministry: babes, little children, young men and fathers. These were categories that did not neatly correlate with those based on biological age. Instead, they denoted degrees of spiritual attainment.