Faith that remains alone -- barren of works is dead and that faith is not genuine faith, but a bare profession of faith. James is simply stating faith that is not accompanied by evidential works is dead. If someone says-claims he has faith but lacks resulting evidential works, then he has an empty profession of faith/dead faith and not authentic faith. (James 2:14-20)
Faith is activated the moment that we place our faith (belief, trust, reliance) in Jesus Christ alone for salvation. Ephesians 2:5 - even when we were dead in trespasses, made us alive together with Christ (by grace you have been saved)... 8 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, 9 not of works, lest anyone should boast.
A distinction without a difference. In James 2:15-16, the example of a "work" that James gives is: "If a brother or sister is naked and destitute of daily food, and one of you says to them, "Depart in peace, be warmed and filled," but you do not give them the things which are needed for the body, what does it profit?" To give a brother or sister these things needed for the body would certainly be a "good work" yet to neglect such a brother or sister and not give them the things needed for the body is to break the second great commandment "love your neighbor as yourself" (Matthew 22:39) as found written in the law of Moses (Leviticus 19:18). Teaching that we are saved by faith + works in general would be works that earn salvation. You can't have it both ways.
..made us alive together with Christ (by grace you have been saved through faith, not works... (Ephesians 2:5-9) Works of obedience FOLLOW faith being activated and made alive with Christ. You have it backwards.
Faith is not dead UNTIL it produces works, which is like saying that a tree is dead UNTIL it produces fruit. Works are not the source of life in faith; rather life in faith is the source of works. Something that is dead cannot produce anything.
In James 2:21, notice closely that James does not say that Abraham's work of offering up Isaac resulted in God's accounting Abraham as righteous. The accounting of Abraham's faith as righteousness was made in Genesis 15:6, many years before his work of offering up Isaac recorded in Genesis 22. The work of Abraham did not have some kind of intrinsic merit to account him as righteous, but it showed or manifested the genuineness of his faith. This is the "sense" in which Abraham was "justified by works." He was shown to be righteous.
In James 2:22, faith made perfect or complete by works means bring to maturity, carry to the end, to complete like love in 1 John 4:18. It does not mean that Abraham was finally saved based on merits of his works after he offered up Isaac on the altar in Genesis 22. When Abraham performed the good work in Genesis 22; he fulfilled the expectations created by the pronouncement of his faith in Genesis 15:6.
*James is discussing the evidence of faith (says-claims to have faith but has no works/I will show you my faith by my works - James 2:14-18), not the initial act of being accounted as righteous with God (Romans 4:2-3).
Romans 5:1 - Therefore, having been justified by faith plus works? NO by faith "apart from additions or modifications" (faith rightly understood in Christ alone) we have peace with God through our Lord Jesus Christ.
My challenge for you: *Please post a scripture that says we are "justified by faith and works" or "saved by faith and works."