Jonathan Edwards is here specifically addressing the question of whether justifying faith is a persevering faith:
. . . [I]t seems manifest that justification is by the first act of faith, in some respects, in a peculiar manner, because a sinner is actually and finally justified as soon as he has performed one act of faith; and faith in its first act does, virtually at least, depend on God for perseverance, and entitles to this among other benefits. But yet the perseverance of faith is not excluded in this affair; it is not only certainly connected with justification, but it is not to be excluded from that on which the justification of a sinner has a dependence, or that by which he is justified. . . .
God in the act of justification, which is passed on a sinner’s first believing, has respect to perseverance, as being virtually contained in that first act of faith and ’tis looked upon and taken by him that justifies, as being as it were a property in that faith that then is: God has respect to the believer’s continuance in faith, and he is justified by that, as though it already were, because by divine establishment it shall follow; and it being by divine constitution connected with that first faith, as much as if it were a property in it, it is then considered as such, and so justification is not suspended; but were it not for this it would be needful that it should be suspended, till the sinner had actually persevered in faith. (from Justification by Faith Alone in Yale-Works 19:201-202, 203 [emphasis mine])
Edwards goes on to note that the justification which takes place at a sinner’s conversion “has respect to” a persevering faith since that justification also has a certain respect to future sins and “infirmities.”