An usefull case of conscience discussed and resolved concerning associations and confederacies with idolaters, infidels, hereticks, or any other known enemies of truth and godlinesse. By Master George Gillespie, late minister at Edinburgh. Whereunto is subjoyned a letter, written by him to the commissioners of the Generall Assembly, in the time of his sicknesse: together with his testimony unto this truth, written two dayes before his death.