Excerpt from The Life of St. Antony:

One day when he had gone forth because all the monks had assembled to him and asked to hear words from him, he spoke to them in the Egyptian tongue as follows: 'The Scriptures are enough for instruction, but it is a good thing to encourage one another in the faith, and to stir up with words. Wherefore you, as children, carry that which you know to your father; and I as the elder share my knowledge and what experience has taught me with you. Let this especially be the common aim of all, neither to give way having once begun, nor to faint in trouble, nor to say: We have lived in the discipline a long time: but rather as though making a beginning daily let us increase our earnestness. For the whole life of man is very short, measured by the ages to come, wherefore all our time is nothing compared with eternal life. And in the world everything is sold at its price, and a man exchanges one equivalent for another; but the promise of eternal life is bought for a trifle. For it is written, "The days of our life in them are threescore years and ten, but if they are in strength, fourscore years, and what is more than these is labour and sorrow. " Whenever, therefore, we live full fourscore years, or even a hundred in the discipline, not for a hundred years only shall we reign, but instead of a hundred we shall reign for ever and ever. And though we fought on earth, we shall not receive our inheritance on earth, but we have the promises in heaven; and having put off the body which is corrupt, we shall receive it incorrupt.