Scripture speaks for what He said:
“Thus also faith by itself, if it does not have works, is dead. For as the body without the spirit is dead, so faith without works is dead also.”
James 2:17, 26 NKJV
[Jas 2:17 KJV] 17 Even so faith, if it
hath not works, is dead, being alone.
[Jas 2:18 KJV] 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.
[Phl 3:9 KJV] 9 And be found in him,
not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
[2Pe 1:1 KJV] 1 Simon Peter, a servant and an apostle of Jesus Christ,
to them that have obtained like precious faith with us through the righteousness of God and our Saviour Jesus Christ:
I think the point you're missing if you read it closely, is that the verse in question does not assert that a faith which produces works is alive. Rather, it makes a subtle but critical distinction: that for a faith to be alive, it must already possess works as a part of itself ("have" or "hath" works - present tense). This nuance shifts the focus away from man's faith and instead highlights the faith of Christ- that His faith, alone contains faith, works, (and righteousness).
The "man" referenced in James 2:18 actually represents Christ. Through this perspective, Christ is stating that if someone claims salvation by their own self-generated faith, then that faith must be perfect and already contain perfect works for it to be genuine and salvation-sufficient (if I can use that phrase). However, the achieving of such perfection is impossible for any man to achieve. Observe, relative to your perspective of James 2:17, that the verse does not quantify a required amount or frequency of faith nor of works to satisfy it. By missing those metrics, the requirements become impossible for man to satisfy. On that basis, the verse on its face would demand requirements yet does not provide the criteria by which they can be satisfied. It would have been incumbent upon the writer were his intention as you stated - that works by man are required - to also provide that criteria, but he didn't. And that omission was not by accident.
In summary, alone Christ is the Savior. He freely imputes His faith, works, and righteousness to those chosen by the Father for salvation at the moment of salvation, as though they are theirs (see Phl 3:9 above). The requirements for faith are fully met in Christ, by His faith—which also contains both works and righteousness—and which alone brought salvation to completion.