God makes room, as it were, in his vineyard for the budding, flourishing, and fruit-bearing of other plants which he hath planted – Great employments call for great exercise of graces. Even in employments in and about providential things, there is the exercise of spiritual grace;—as much faith and prayer, as much communion with God, walking before him, and wrestling with him, may be used in casting down of armies, as in setting up of churches. God exerciseth all the graces of his in the work he calleth them out unto. He principles them by faith and fellowship with himself for their employment; and therefore he gives each individual but his appointed season, that others, in whose hearts he hath lodged the same spirit wherewith they are endued, may come forth and show the fruits thereof.
~John Owen
from a sermon entitled The Labouring Saints Dismission To Rest; Volume 8, pages 354-5