William Perkins (1558-1602) is known as the father of Elizabethan Puritanism.  One of his most important works is the Reformed Catholik.  Perkins devoted an entire section in this work to the Reformed doctrine of assurance.  As I was reading this treatise, I was struck by how contrary Perkin's comments are to the Westminster Confession of Faith on Assurance.  Perkins is adamant that assurance belongs to the essence of true faith.  Read the following statements by Perkins and then compare them with the WCF. 
Here is what Perkins writes:

True faith is both an infallible assurance, and a particular assurance of the remission of sins, and of life everlasting. And therefore by this faith, a man may be certainly and particularly assured of the remission of sins, and life everlasting.  That this reason may be of force, two things must be proved: first, that true faith is certain assurance of God's mercy to that party in whom it is.  Second, that faith is a particular assurance thereof. 

For the first, that faith is a certain assurance, Christ said to Peter, Matt. 14:31, O thou of little faith, wherefore didest thou doubt? Where he makes an opposition between faith and doubting thereby giving us directly to understand, that to be certain, and to give assurance is of the nature of faith.  Rom. 4:20-22, Paul says of Abraham that he did not doubt the promise of God through unbelief, but was strengthened in faith, and gave glory to God being fully assured, that he which promised was able to do it, where I observe first that doubting is made a fruit of unbelief. Therefore, infallible certainty and assurance, being contrary to doubting, must proceed from true faith, considering that contrary effects come of contrary causes, and contrary causes produce contrary effects.

Second, I note, that the strength of Abraham's faith, did stand in fullness of assurance; for the text says, he was strengthened in the faith, being fully assured. And again, Heb 11:1, true saving faith is said to be the ground and substance of things hoped for, and the evidence or demonstration of thing that are not seen. But faith can be no ground or evidence of things, unless it be for nature certainty itself...That saving faith is a particular assurance is proved by this, that the property of faith is to apprehend and apply the promise, and the thing promised, Christ with his benefits..."
William Perkins, The Workes: A Reformed Catholike, Vol. I (John Legatt: London, 1616) 564.

Here is Westminster Confession of Faith 18:3,

III. This infallible assurance does not so belong to the essence of faith, but that a true believer may wait long, and conflict with many difficulties, before he be partaker of it:[10] yet, being enabled by the Spirit to know the things which are freely given him of God, he may, without extraordinary revelation in the right use of ordinary means, attain thereunto.[11] And therefore it is the duty of every one to give all diligence to make his calling and election sure,[12] that thereby his heart may be enlarged in peace and joy in the Holy Ghost, in love and thankfulness to God, and in strength and cheerfulness in the duties of obedience,[13] the proper fruits of this assurance; so far is it from inclining men to looseness.[14]

What Perkins says appears to be in direct conflict with the Westminster Confession. The WCF says assurance does not so belong to the essence of faith, whereas Perkins says assurance belongs to the nature of it and is for nature certainty itself.  Perkins seems to be more consistent with what the early Reformers and continental tradition believed on the issue of assurance (Calvin never said anything like what the WCF does on assurance).  But considering that Perkins is known as the father of Elizabethan Puritanism, this divide made by the WCF appears to be a departure from earlier Reformed thought on the doctrine of assurance. So was this a serious compromise made by the assembly on the article of assurance?   What are your thoughts on the direct conflict here exposed between Perkins and the WCF?  And, what are the consequences of saying that assurance can be separated from true faith?  In other words, can the direct act of believing be separated from the reflex act of knowing that you believe?  Who is right here?