The Catechism of the Catholic Church #956 says about the Saints "Being more closely united to Christ, those who dwell in heaven fix the whole Church more firmly in holiness. They do not cease to intercede with the Father for us, as they proffer the merits which they acquired on earth through the one mediator between God and men, Christ Jesus. So by their fraternal concern is our weakness greatly helped."
This shirt features an icon of the Saints surrounding Christ and Latin text from the Litany of Saints (Litaniae Sanctorum) emploring the intercession of the Saints.
"Omnes Sancti et Sanctae Dei, intercedite pro nobis." which translate to "All you holy men and women, Saints of God, intercede for us."