In the parable of the sheep and the goats (Matthew 25:31-46), all nations of the world are gathered. The people of these nations are then placed into only two categories: sheep, which are termed righteous, and goats, which are not. Sheep and goats are described in the parable to differ in only one important way. Sheep did good works, depicted in the parable as various ways of helping others. Goats did not. Nothing is said about sheep and goats differing in faith, which is usually thought by Christians to be the factor that engenders righteousness. But even though faith isn’t mentioned, it’s likely present in at least some of the parable’s subjects. So, subjects can be placed into groups reflecting the four possible combinations of faith and works: a combination positive for both faith and works (A), a combination positive for faith but negative for works (B), a combination negative for faith but positive for works (C), and a combination negative for both faith and works (D).
Sheep would clearly include A and goats would clearly include D. But how are B and C handled? As it turns out, whatever their placement, problems arise.
If B (+faith; - works) is included with sheep, the parable’s associating sheep only with works would be contradicted. On the other hand, if B is included with goats, faith would not be seen as a sufficient condition of righteousness because B, which has faith, would not, as goats, be considered righteous. As such, this finding would contradict Christian belief that faith is a sufficient condition of righteousness, i.e., the belief that if one has faith, one will be righteous.
If C (-faith; + works) is included with sheep, faith would not be seen as a necessary condition of righteousness because C, which has no faith, would, as sheep, be considered righteous. As such, this finding would contradict Christian belief that faith is a necessary condition of righteousness, i.e., the belief that if one is righteous, one would have faith. On the other hand, if C is included with goats, the parable’s associating works only with sheep would be contradicted.
One way out of this problem is to show that faith is a sufficient and necessary condition of works, so that faith would imply works and works would imply faith. Then the four possible combinations of faith and works would be reduced to just two, i.e., A and D, and their placement into sheep and goats, respectively, would be unambiguous. Combinations B and C–the combinations causing the problems–would not logically exist.
Can faith be shown to be a sufficient and necessary condition of works? Many Christians believe that faith is a sufficient and necessary condition of works. But, straightforward observations seem to indicate otherwise. For example, the setting of the sheep and goats parable suggests that Jesus was chastising the Jewish leaders of that time who had faith but not the works emphasized by Jesus. These people could be envisioned as combination B (+faith; - works). Further, moral people of no faith exist and account for combination C (-faith; + works).
Thus, solving this problem by showing faith is a sufficient and necessary condition of works may not be possible.