Your question, Why is faith without works dead?
To comprehend the significance of this scripture, revisit the text preceding verse 24. There are two key concepts you must grasp.
First where and when does a person receive his faith that generates works? Secondly what are the works that come from having faith?
Once a person accepts Jesus as their Lord and Savior, they receive the Holy Spirit to reside within them.
The Holy Spirit imparts the fruits of the Spirit to us, and one of those fruits is faith. This is true faith.
God grants each of us a portion of his faith, as per his divine will.
Roman 12:3 “For I say, through the grace given unto me, to every man that is among you, not to think of himself more highly than he ought to think; but to think soberly, according as God hath dealt to every man the measure of faith.”
So true faith is given to us by God through his Holy Spirit.
Many people believe in God and Jesus but have never personally received them. Their faith isn’t based on God’s revelation but rather an acknowledgment of their existence.
The fruits of the Holy Spirit, given to all of God’s children, produce works. These are not works of the flesh, but rather works generated by and through the Holy Spirit.
Verse 24 “You see then how that by works a man is justified, and not by faith only.