From Homily 11, Homilies on First Thessalonians.

“Paul says, ’Quench not the Spirit,’ that is, the gift of grace, for it is his custom so to call the gift of the Spirit. But this an impure life extinguishes. For as anyone, who has sprinkled both water and dust upon the light of our lamp, extinguishes it, and if he does not this, but only takes out the oil — so it is also with the gift of grace. For if you have cast over it earthly things, and the cares of fluctuating matters, you have quenched the Spirit.… The oil fails, when we do not give alms, the Spirit is quenched. For it came to you as an alms from God. Then He sees this fruit not existing in you, and he abides not with an unmerciful soul… 

Does Christ not disdain to call them to his table with the king — for both are called together — and you perhaps disdain even to be seen giving to the poor, or even conversing with them?  Be ashamed of your haughtiness and pride!  See that we suffer not the same with the rich man formerly.  He disdained even to look upon Lazarus and did not allow him to share his roof or shelter, but he was without, cast away at his gate, nor was he even granted a word from him. But see how, when fallen into straits, and in want of his help, he failed to obtain it. For if we are ashamed of those of whom Christ is not ashamed, we are ashamed of Christ, being ashamed of his friends. Let your table be filled with the maimed and the lame. Through them Christ comes, not through the rich. 

Saint John Chrysostom (ca. 347-407) was Archbishop of Constantinople, and one of the greatest preachers of his era. He is traditionally counted among the Four Great Doctors of the Eastern Church.  The Homilies on I Corinthians date from his ministry in his native Antioch, and were preached in the 380s and 390s. In the Kalendar of the Episcopal Church, he is commemorated on September 13.