The following quotes come from a little known sermon by Jonathan Edwards, entitled "Persevering Faith." Unfortunately it is not published in the Works of Jonathan Edwards or any popular compilations of JE's sermons; it is only available in the Works published by Yale, which are quite expensive:
"[Perseverance] 'tis necessary to salvation as a necessary consequence and evidence of a title to salvation. There never is a title to salvation without it. Though it have not the righteousness by which a title to life is attained, yet none have that righteousness that don't persevere; and that because although it is not proper to say that perseverance is necessary in order to justification, yet a persevering principle is necessary in order to justification...'Tis necessary that a man should believe in Christ, and cleave to Christ in a persevering way: a temporary faith don't justifiy. But in order to that, persons must have that faith that is of a persevering, everlasting sort. He must have that sort of seed that is an abiding seed. 'Tis not a vanishing but a durable faith that justifies."
"Perseverance is necessary to salvation, as 'tis a necessary prerequisite to the actual possession of eternal life. A way of persevering holiness is the way to glory, and the only way to it; and 'tis impossible that we should arrive at glory without going to it in a way of persevering holiness, as 'tis impossible that we should go from one town to another without passing the ground that is between one and the other. We read of the strait gate and the narrow way. 'Tis necessary that both should be passed, before we obtain a crown of glory. God hath set up that crown of glory at the end of a race; and therefore he that stops short of the end of the race and turns back, and so never comes to the end of the race, will never come to the crown. And so 'tis necessary for every Christian, that he should finish his course...Perseverance in holiness is a necessary prerequisite to glory."
"Those promises of eternal life to perseverance are for the comfort of the saints, for the more a person by experience finds that his goodness if of a persevering kind, the more evidence has he of his title to life."
"A hypocrite's faith is but a temporary faith."
"A godly man ordinarily lives a holy life, which implies not only negative, but positive religion." [my italics]
"Though it be promised that true saints shall be so influenced and assisted, as that they shall persevere; yet this is one MEANS by which God influences them, viz. counsels and warnings against falling away."