“Quench not the spirit,” says the Word of God. Let every Christian, especially every priest and instructor of children, remember this. We who are priests must especially burn with the spirit in our high service to God and mankind. How much we might have done for God, for men, and for ourselves, if we had applied ourselves to our work with faith and love, zealously, warmly, energetically! And how little, dry, fruitless, will be our service if we do our work indolently, slothfully, coldly, without any zeal and energy! We shall have much to answer for before God, both for ourselves and for those intrusted to our care.

St. John of Kronstadt, My Life in Christ

Hat tip: Rdr. Andrew T