In Matthew 25:31-46 (a passage subtitled "The Sheep and the Goats" in the NIV), Jesus seems to be drawing a direct relationship between good works and salvation.
Matthew 25:31-46 NIV:
31 “When the Son of Man comes in his glory, and all the angels with him, he will sit on his glorious throne. 32 All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. 33 He will put the sheep on his right and the goats on his left.
34 “Then the King will say to those on his right, ‘Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. 35 For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, 36 I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.’
37 “Then the righteous will answer him, ‘Lord, when did we see you hungry and feed you, or thirsty and give you something to drink? 38 When did we see you a stranger and invite you in, or needing clothes and clothe you? 39 When did we see you sick or in prison and go to visit you?’
40 “The King will reply, ‘Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me.’
41 “Then he will say to those on his left, ‘Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels. 42 For I was hungry and you gave me nothing to eat, I was thirsty and you gave me nothing to drink, 43 I was a stranger and you did not invite me in, I needed clothes and you did not clothe me, I was sick and in prison and you did not look after me.’
44 “They also will answer, ‘Lord, when did we see you hungry or thirsty or a stranger or needing clothes or sick or in prison, and did not help you?’
45 “He will reply, ‘Truly I tell you, whatever you did not do for one of the least of these, you did not do for me.’
46 “Then they will go away to eternal punishment, but the righteous to eternal life.”
I read this passage to say that those people who cared for those in need will have eternal life; those people who did not will have eternal punishment.
How does this passage reconcile with other passages in the New Testament that imply or directly state that salvation is through faith in Jesus (e.g. Luke 23:40-43 -- the thief on the cross; Ephesians 2:8-9 -- salvation through faith, not works)?