Final answer:
John Winthrop's overall message in his sermon was emphasizing the importance of community and unity, as he intended to create a Puritan 'city upon a hill' that exemplified Christian virtues.
Step-by-step explanation:
John Winthrop's overall message in his sermon "A Modell of Christian Charity" was the necessity for creating a unified community living by Christian principles. Rather than advocating for religious tolerance or separation of church and state, Winthrop's vision was centered around forming a Puritan 'city upon a hill' that would be a model of moral virtue and religious piety. This ties back to the Puritan concept of a covenant with God, with the social and civil bonds within the community serving as reflections of their religious commitment. Winthrop's goal was to establish a society that would live in close adherence to their understanding of Scripture, and the importance of community and unity was paramount to this end.