Imitation of Christ

Si pietatis causa, aut fraternæ utilitatis proposito, quandoque consuetum omittitur exercitium, facile postea poterit recuperari. Si autem tædio animi, vel negligentia faciliter relinquitur, satis culpabile est et nocivum sentitur. Conemur quantum possumus, adhuc leviter deficiemus in multis. Semper tamen aliquid certi proponendum est, et proponenda sunt illa præcipue quæ amplius nos impediunt. Exteriora nostra et interiora pariter nobis scrutanda sunt, et ordinanda, quia utraque expediunt ad proprium profectum. 
 

If a holy exercise is sometimes omitted for the sake of some act of piety, or of some brotherly kindness, it can easily be taken up afterwards; but if it be neglected through distaste or slothfulness, then is it sinful, and the mischief will be felt. Strive as earnestly as we may, we shall still fall short in many things. Always should some distinct resolution be made by us; and, most of all, we must strive against those sins which most easily beset us. Both our outer and inner life should be straitly examined and ruled by us, because both have to do with our progress.

Imitation of Christ, I, 19:3