In today's Gospel, we read how when the Lord returns with all his angels on that last day at the end of time, "all nations" shall be gathered before His Throne to be judged. On that great and dreadful day, he shall separate the "sheep" from the "goats." On His right hand shall stand those who have fed the hungry, given drink to the thirsty, clothed the naked, given hospitality to strangers, visited the sick and those in prison. These are the sheep who shall be blessed to enter into God's eternal Kingdom, because what they have done on behalf of the least of our Lord's brethren, they have done unto Him. Those on His left hand--the goats--shall be cast into the eternal fires... because they have failed to perform these practical acts of charity.
Now it would be easy and tempting to take this passage as a "to do" list of those good deeds we must do if we desire to be saved--but such an interpretation would constitute a misunderstanding of our Lord's intent. These are, indeed, all virtuous acts pleasing to God--but only if they truly are works of charity--that is, an outward expression of our love toward God and neighbor. As St. Paul writes, we are saved by faith, not works. Nevertheless, he also insists that "faith without works is dead." God, you see, judges us not primarily according to our outward actions, but rather according to the inner disposition of our heart.
Our Lord in no way implies in this passage that we need not bother with prayer, fasting and regular participation in the sacramental life of the Church: these are, indeed, essential means for the softening of our hearts, preparing them to receive the fullness of God's love--without which all of our good deeds are done in vain.
Good deeds done apart from God--not as a pure and spontaneous expression of the love that dwells within us--will quickly become a source of pride and a means to acquire the admiration of our fellow man. When this happens, we have already received our reward.
Strive, then, to acquire the love of God in your heart, and all else will follow as day follows night. Only then shall we begin to be merciful, even as our heavenly Father is merciful. For truly, the only insurmountable obstacle to our salvation is our failure to love. If we truly love God with all our heart, soul and mind--and our neighbor as our very own self --we shall with joy and gladness naturally fulfill His commandments. Only thus shall we be found worthy on that Last Day to enter into His eternal Kingdom.