The text on which Cushman’s sermon was preached was, Let no man seek his own, but every man another's wealth (I Corinthians 10:24). "The occasion of these words of the Apostle Paul, was because of the abuses which were in the Church of Corinth. Which abuses arose chiefly through swelling pride, self-love and conceitedness. … It is lawful sometimes for men to gather wealth, and grow rich, even as there was a time for Joseph to store up corn, but a godly and sincere Christian will see when this time is, and will not hoard up when he seeth others of his brethren and associates to want, but then is a time, if he have anything to fetch out and disperse it. … bear ye therefore one another's burthen, and be not a burthen one to another, avoid all factions, frowardness, singularity and withdrawings, and cleave fast to the Lord, and one to another continually; so shall you be a notable president to these poor heathens, whose eyes are upon you, and who very brutishly and cruelly do daily eat and consume one another, through their emulations, ways and contentions; be you therefore ashamed of it, and win them to peace both with yourselves, and one another, by your peaceable examples, which will preach louder to them, then if you could cry in their barbarous language, so also shall you be an encouragment to many of your christian friends in your native country, to come to you, when they hear of your peace, love and kindness that is amongst you: but above all, it shall go well with your souls, when that God of peace and unity shall come to visit you with death as he hath done many of your associates, you being found of him, not in murmurings, discontent and jars, but in brotherly love, and peace, may be translated from this wandering wilderness unto that joyful and heavenly Canaan."
Cushman's audience had been struggling in the wilderness under the burdens of the London contract for an entire year. But like Winthrop's much more famous Modell of Christian Charity a decade later, Cushman's sermon exhorted its listeners to Christian love and selfless cooperation for the welfare of the whole. In Cushman's case the good of the whole would be achieved by sacrificial and charitable attitudes and actions toward both fellow settlers at Plymouth and unreliable partners in London. But, as it turned out, Christian love and charity, under the restraints of an unfavourable business contract, were a mixed blessing for ordinary people of mean estates. Such virtues may have been the way to heaven but were decidedly not the way to a full belly, and Plymouth's people were eager for both rewards. This was not clear to Robert Cushman; it was only too clear to Governor Bradford: most settlers in Plymouth were poor, and the partnership with Londoners kept them so. The Pilgrims' purpose in America could be served in several ways, but the colonists quickly concluded that the "common course and condition" laid down by the investors in London was not one of them. Circumstances in early Plymouth dictated a rough equality. Curiously, it was at odds with conventional thinking about God's design for his people, and it tended to erode as conditions first worsened and then, through individual effort, improved. Bradford concluded that because all of Plymouth's settlers were treated alike and were expected to respond alike, "they thought themselves in the like condition, and one as good as another" -- a condition Cushman in London would have applauded, were Christian virtue the motive. But, the governor went on, although the equalitarian tendency did not altogether erase those arbitrary distinctions that “God hath set amongst men, yet it did at least much diminish and take off the mutual respects that should be preserved amongst them.” To Bradford this was a fundamental contradiction; the "common course and condition" worked against divine doctrine about human differences that existed for the common good. Cushman's sermon contained repeated warnings that selfish individualism, a shifting for oneself, could only destroy the spiritual league and covenant of love and sacrifice and lead to the colony's demise. The Pilgrims' response to Cushman's plea was almost immediate, and positive: the settlers accepted the offered contract. But absolute commitment to the "common course and condition" for the good of the whole soon faded before more secular realities of the New World struggle. Bradford with a great deal of sorrow explained that "God in His wisdom saw another course fitter for them." Given the abundance of land and resources -- once settlers learned to use them -- there probably was no other way.
Cushman’s sermon was first printed in England (1621) and later in America (Boston, 1846). The latter half of the sermon, on the sweetness of friendship, does not seem to have been included in either of the publications. I have spent some time trying to see if any of that part of the sermon has survived, and it does not appear that any of it has.