God also willed that we pray through the saints, and that the saints prayed for us. This was to give confidence to the fearful, so that those who dare not or cannot ask by themselves may succeed through suitable intercessors. In this way, humility would be preserved in those who pray, dignity manifested in the saints who intercede, and love and unity displayed in all the members of Christ, by which the lower have faithful recourse to the higher while the higher generously condescend to the lower.
[St. Bonaventure, Breviloquium (5.10.3), Monti, tr., Franciscan Institute Publications (St. Bonaventure, NY: 2005) p. 208.]