Dr. Burns has written an excellent work on Adoniram Judson called: "A Supreme Desire to Please Him: The Spirituality of Adoniram Judson." You can purchase it here:
https://www.amazon.com/Supreme-Desire-Please-Him-Spirituality-ebook/dp/B01MY5ERX8
Adoniram Judson was not only a historic figurehead in the first wave of foreign missionaries from the United States and a hero in his own day, but his story still wins the admiration of Christians even today. Though numerous biographies have been written to retell his life story in every ensuing generation, until now no single volume has sought to comprehensively synthesize and analyze the features of his theology and spiritual life. His vision of spirituality and religion certainly contained degrees of classic evangelical piety, yet his spirituality was fundamentally rooted in and ruled by a mixture of asceticism and New Divinity theology. Judson's renowned fortitude emerged out of a peculiar missionary spirituality that was bibliocentric, ascetic, heavenly minded, and Christocentric. The center of Adoniram Judson's spirituality was a heavenly minded, self-denying submission to the sovereign will of God, motivated by an affectionate desire to please Christ through obedience to his final command revealed in the Scriptures. Unveiling the heart of his missionary spirituality, Judson himself asked, "What, then, is the prominent, all-constraining impulse that should urge us to make sacrifices in this cause?" And he answered thus: "A supreme desire to please him is the grand motive that should animate Christians in their missionary efforts."