In order to make great advance in this way, and to be able to ascend to the mansions we desire, we must remember that the business does not consist in thinking, but in loving much; do therefore whatever may excite you most to love. Perhaps we do not know what love is; and I do not wonder at it, for it consists not in having greater delights, but greater resolutions and desires of pleasing God in everything, and in endeavouring, as much as possible, not to offend Him, and in beseeching Him that He would promote the honour and glory of His Son, and extend the bounds of the Catholic Church. These are signs of love. Do not imagine that it consists in not thinking on anything else, and that all is lost if you have a few distractions.
Teresa of Ávila, Saint, and John Dalton. The Interior Castle. London: T. Jones, 1852.