Intercession of the Saints is a doctrine held by the Eastern Orthodox, Oriental Orthodox, and Roman Catholic Churches. The practice of praying through Saints can be found in Christian writings from the 3rd century onward. The 4th-century Apostles' Creed states belief in the communion of Saints, which certain Christian churches interpret as supporting the intercession of Saints. As in Christianity, this practice is controversial in Judaism and Islam.
According to proponents of the doctrine of Intercession of Saints, what are the strongest apologetic arguments for the veracity of the doctrine? Are there compelling reasons that should be able to persuade any rational believer to seek intercession support from departed Saints?
Note: the counterpart question can be found at According to Protestantism, what are the strongest apologetic arguments against the doctrine of Intercession of Saints?