What is an overview of Protestant explanations of the difference between dead faith and perfect faith in James 2? In James 2:17-22 (KJV) it reads:


  17 Even so faith, if it hath not works, is dead, being alone.
  
  18 Yea, a man may say, Thou hast faith, and I have works: shew me thy
  faith without thy works, and I will shew thee my faith by my works.
  
  19 Thou believest that there is one God; thou doest well: the devils
  also believe, and tremble.
  
  20 But wilt thou know, O vain man, that faith without works is dead?
  
  21 Was not Abraham our father justified by works, when he had offered
  Isaac his son upon the altar?
  
  22 Seest thou how faith wrought with his works, and by works was faith
  made perfect?


From the Protestant perspective, what is the difference between "dead" faith (as described in verses 17 and 20) and "perfect" faith (as described in verse 22)?

For example, how do you tell them apart, and what are the outcomes of these different kinds of faith?

(Related)

Edit: Since different Protestants believe different things, an overview of the different viewpoints, and which denomination believe them.
The Protestant ‘Westminster Confession of Faith’ was drawn up in 1647-8 and a very considerable collection of Protestant denominations subscribe to it, so I will simply quote from this book for classes studying it. The relevant Articles are quoted, followed by the author’s further clarifications as to what the Articles mean.


  XIV. OF SAVING FAITH
  1.  The grace of faith, whereby the elect are enabled to believe to the saving of their souls, is the work of the Spirit of Christ in
  their hearts…
  2.  By this faith, a Christian believeth to be true whatsoever is revealed in the word, for the authority of God himself speaking
  therein; and acteth differently upon that which each particular
  passage thereof containeth; yielding obedience to the commands,
  trembling at the threatenings, and embracing the promises of God for
  this life and that which is to come. But the principal acts of saving
  faith are, accepting, receiving, and resting upon Christ alone for
  justification, sanctification, and eternal life, by virtue of the
  covenant of grace.
  3.  This faith is different in degrees, weak or strong; may be often and many ways assailed and weakened, but gets the victory...


The author of the Study Guide then explains (with regard to faith)


  …there can be no true repentance without faith in Christ… In the realm
  of faith, as in that of repentance, some have intruded the doctrine of
  human ability and merit. But as John Murray has said, ‘Faith is not
  something that merits the favour of God. All the efficacy unto
  salvation resides in the Saviour. As one has aptly and truly stated
  the case, it is not faith that saves but faith in Jesus Christ;
  strictly speaking, it is not even faith in Christ that saves but
  Christ that saves through faith’ (Redemption Accomplished and Applied,
  p. 139).


That is a typically Protestant view of saving faith, perfect faith – as opposed to a ‘dead’ faith. Perfect faith acts in accordance with God’s commands. Christians have different degrees of faith, some are weak in faith, yet “he who has begun a good work in you will carry it on to completion until the day of Christ Jesus” – Philippians 1:6.  Now here is the view of good works, as related to such a living, saving faith:


  XVI.  OF GOOD WORKS
  1.  Good works are only such as God hath commanded in his holy word, and not such as, without the warrant thereof, are devised by men out
  of blind zeal, or upon any pretence of good intention.
  2.  These good works, done in obedience to God’s commandments, are the fruits and evidence of a true and lively faith: and by them believers
  manifest their thankfulness, strengthen their assurance, edify their
  brethren, adorn the profession of the gospel, stop the mouths of the
  adversaries, and glorify God, whose workmanship they are created in
  Christ Jesus thereunto; that, having their fruit unto holiness, they
  may have the end eternal life.
  5.  We cannot, by our best works, merit pardon of sin, or eternal life, at the hand of God, by reason of the great disproportion that is
  between them and the glory to come, and the infinite distance that is
  between us and God, whom by them we can neither profit nor satisfy for
  the debt of our former sins… as they are good, they proceed from the
  Spirit; and as they are wrought by us, they are defiled and mixed with
  so much weakness and imperfection, that they cannot endure the
  severity of God’s judgment.
  6.  Yet notwithstanding, the persons of believers being accepted through Christ, their good works also are accepted in him…


The author of the Study Guide goes on to ask, 


  What are ‘good works’?  …It is commonly thought that anything done out
  of charity or kindness qualifies as a ‘good work.’ But according to
  the Scripture it is not so. Two requirements are set forth in
  Scripture in order that a work may be truly ‘good’. (1) It must be in
  conformity with the revealed will of God… (2) It must also spring from
  a ‘good conscience’. It must be that which is done with sincerity of
  heart as an act of service to God… The Christian’s ability to do good
  works is not of himself but only of the Holy Spirit who dwells in him…
  But to say that the generative source of all our good works is God is
  in no way to suggest that negligence, slothfulness, or carelessness is
  excusable, as if we were not bound to perform any duty unless we feel
  a special motion of the Holy Spirit directing us thereunto... The
  marvel is not that the good works of believers are so ‘great,’ but
  rather that they are accepted and rewarded at all. If even ‘our
  righteousnesses are as filthy rags (Isaiah 64:6), if even our best
  works are ‘defiled and mixed with much weakness and imperfection,’ how
  is it that they are even called good works at all? The answer is that
  believers have union with Christ… As A.A. Hodge has put it: ‘It is all
  of grace – a grace called a reward added to a grace called a work.’
  That is, both are of God. ‘God promises to reward the Christian just
  as a father promises to reward his child for doing what is its duty,
  and what is for its own benefit alone…’ (Commentary on the Confession
  of Faith, p. 228). (Source: Williamson, G.I., The Westminster
  Confession of Faith for Study Classes pp 96-7, 100, 117, 120, 122 –
  Presbyterian and Reformed Publishing Co., 1964)


Protestants would say that Abraham’s faith was ‘perfected’ by being so prepared to do what God commanded, that such a work of obedience (to sacrifice his miracle child) glorified God. Thus God stopped Abraham from actually sacrificing the child of promise as his actions were based on faith in the resurrection of the dead; he had a living faith, not merely an intellectual assent to truths.

I hope others will give more of an overview of Protestant explanations as this very abbreviated series of extracts from the Westminster Confession of Faith does not really do justice to this huge subject. But let it be known that Protestants know full well that if they truly have saving faith, they will do good works as evidence of having been given such faith, and that both the receiving and the doing are gifts of God, for His glory.