I thought this was particularly challenging. It is from the Letters of John Newton (pp. 26-27), describing the heart of the person singularly focused on the glory of God and the advancement of the gospel.
“A palace would be a prison to him without the Lord’s presence, and with this a prison would be a palace.
Therefore he is not afraid of evil tidings; but when the hearts of others shake like the leaves of a tree, he is fixed, trusting in the Lord, who he believes can and will make good every loss, sweeten every bitter, and appoint all things to work together for his advantage. He sees that the time is short, lives upon the foretastes of glory, and therefore accounts not his life, or any inferior concernment, dear, so that he may finish his course with joy.
Now, in proportion as we advance nearer to him, our judgment, aim, and end, will be conformable to his, and his glory will have the highest place in our hearts.
He has a desire to depart and to be with Christ, which would be importunate if he considered only himself; but his chief desire is, that God may be glorified in him, whether by his life or by his death. He is not his own; nor does he desire to be his own; but so that the power of Jesus may be manifested in him, he will take pleasure in infirmities, in distresses, in temptations; and though he longs for heaven, would be content to live as long as Methuselah upon earth, if, by any thing he could do or suffer, the will and glory of God might be promoted.
And though he loves and adores the Lord for what he has done and suffered for him, delivered him from, and appointed him to; yet he loves and adores him likewise with a more simple and direct love, in which self is in a manner forgot, from the consideration of his glorious excellence and perfections, as he is in himself. That God in Christ is glorious over all, and blessed for ever, is the very joy of his soul; and his heart can frame no higher wish, than that the sovereign, wise, holy will of God may be accomplished in him, and all his creatures. Upon this grand principle his prayers, schemes, and actions, are formed.”