Whitefield wrote to Piers--
Let me exhort you, by the mercies of God, to continue unwearied in well-doing. You have seen the afflictions of God's spiritual Israel. 'Do and Live' is the most they hear, and what is this but requiring them to make bricks without straw?--quoted in Arnold Dallimore, George Whitefield: The Life and Times of the Great Evangelist of the 18th Century Revival (2 vols; Banner of Truth, 1970, 1980), 1:397-98
Arise, arise then, my dear Mr Piers and proclaim the Lord to be their righteousness. . . . Fear not the face of man. . . . I hope my dear friend ere now hath prevented my exhortations. Methinks I see him, with all boldness, declaring the whole counsel of God and the attentive people joyfully receiving the gracious works which proceed out of his mouth.