I find Perkins to strike a wonderful yet exceedingly simple balance here. Like many other divines, Perkins does not march straight to the syllogismus practicus for assurance of our election, or of our adoption in Christ, thus seeking a witness to the execution of the decree outside of Christ and in us. Rather, he (as Calvin and others) states that assurance stems primarily from the Holy Spirit (or from faith); and it is only when this fails that we take recourse to looking into ourselves for signs to assure us.
Here some will demand howe a man may be assured of his adoption, if he want the testimonie of the Spirit to certifie him thereof. Ans. Fire is knowne to be no painted but a true fire, by two notes: by heate, and by the flame: now if the case fall out that the fire want a flame, it is still knowne to be fire by the heate. In like manner, as I haue saide, there be two witnesses of our adoption: Gods Spirit, and our spirit. Now if it fall out that a man feele not the principall, which is the spirit of adoption, hee must then haue recourse to the second witnesse and search out in himselfe the signes & tokens of the santification of his owne spirit, by which he may certenly assure himselfe of his adoption; as wee know fire to be fire by the heat though it want a flame. (from Exposition of the Creed; Predestination. p.344 in the collected works volume.