St. John of Kronstadt 1829-1908
To our shame, we must admit that in many Orthodox Christians the Orthodox Faith is not only absent in their heart, but it is also not on their tongue; among them it has vanished entirely, or has been turned into total indifference with regard to any religion whatever–Catholic, Lutheran, Jewish, Mohammendan, or pagan. We hear that one may please God in every religion, i.e., that every religion is supposedly pleasing to God, and that falsehood and truth, righteousness and unrighteousness are matters about which God does not care.
This is what ignorance of their own Faith, ignorance of the spirit and history of their Church, estrangement from its life and divine services, has brought many to–an eclipse of any understanding of Orthodoxy, heterodoxy and other religions! (On the Joy of Being Orthodox)
My brothers, only the Orthodox Faith purifies and sanctifies human nature corrupted by sin, renews the decayed, enlightens the darkened, heals those wounded by sin, warms the frozen, and unites those separated from God. (The Rush to Embrace by Fr. Alexey Young, p. 86)