Work is after faith, not before. If one don't have a faith than why work.
Real faith cause work if it possible, but if one have a faith than die in the same second, he still save, because faith is the requirement not work.
These 10 lepers had "faith" Jesus would cleanse them, notice in the following verse they were not yet cleansed, but all did the works of going to show the priests they were cleansed (and yet as they left they had not yet been cleansed showing some degree of faith), it was not until (it came to pass) "as they went" they were cleansed :
Luke 17:14 (KJV)
14 And when he saw
them, he said unto them, Go shew yourselves unto the priests. And
it came to pass, that, as they went, they were cleansed.
These lepers (all 10) were cleansed, but 1 out of the 10 ran back to Jesus, praising God giving God thanks :
Luke 17:15-18 (KJV)
15 And one of them, when he saw that he was healed, turned back, and with a loud voice glorified God,
16 And fell down on
his face at his feet, giving him thanks: and he was a Samaritan.
17 And Jesus answering said, Were there not ten cleansed? but where are the nine? 18 There are not found that returned to give glory to God, save this stranger.
this "righteous works" of this 1 man out of the 10 men was saved, notice the following verse the word "whole" which is translated from the Greek word "σεσωκεν" (sozo) which means "saved" :
Luke 17:19 (KJV)
19 And he said unto him, Arise, go thy way:
thy faith hath made thee whole.
9 men, show of faith (they had to believe Jesus would heal them or they would not have headed for the priests, they were not yet healed until being on their way to see the priests Luke 17:14) and even though healed were not saved) no righteous works, not saved even with faith.
1 man out of 10 that showed faith in the Lord same as the other 9 and was healed, showed righteous works by returning to Jesus and giving "glory to God" (Luke 17:17-18) :
Luke 17:17-18 (KJV)
17 And Jesus answering said, Were there not ten cleansed? but where
are the nine?
18 There are not found that returned to give glory to God, save this stranger.
BECAUSE OF this one mans RIGHTEOUS WORKS (returning to Jesus praising God, a work the others that were healed did not do) was made "whole" (Greek word "σεσωκεν" (sozo) meaning "saved").
Luke 17:19 (KJV)
19 And he said unto him, Arise, go thy way: thy faith hath made thee whole.
So "faith alone" did not save this 1 man, "faith with empty works" did not save this man (the other 9 were healed but not saved by empty faith as well this man), but AFTER "faith" AND THEN AFTER "righteous works" of RETURNING TO GLORIFY GOD, was this man "σεσωκεν" made whole (different from the other 9) "saved".
Faith alone will never save anyone just like it did not save the 9.