Charles Spurgeon Commentary Matthew 25:45

"Then shall he answer them, saying, Verily I say unto you, Inasmuch as ye did it not unto one of these least, ye did it not unto me." — Matthew 25:45 (ASV)

Our Lord does not mean to teach that people will be condemned because they have not been charitable to the poor and needy, or that they will be saved if they are generous and openhanded. That would indeed be salvation by works, to be boasted of for all eternity. He does mean that only those who produce such fruit as this prove that “the root of the matter” is in them; by ministering to His poor brethren, out of love for Him, they show that they are the subjects of that distinguishing grace which makes them differ from others. All our future depends on our relationship to the Lord Jesus Christ.