The Church and her Sacraments are the only means given to us specifically for salvation. We are bound to the Church and it is our surest hope for heaven.
But God is not bound by the Church. He can work in other ways, drawing people to Himself. We cannot be sure about the salvation of those outside of the visible Church. Obviously they would do better to accept the Truth of the Church, which is why it is essential that we evangelize, that they too may have access to the abundant graces of the Sacraments. But we cannot question the Mercy of God and the possibility that non-Catholics or even non-Christians may be lead into the Body of Christ through some other means. The Body of Christ in heaven is a continuation of His Body on earth. All who are saved must be saved in the Church (in Christ), either here on earth (visibly as members of the Church) or, more precisely, we will all be members of that one Body in heaven. We are given the Church as a point of access to the Body, but if God desires others to attain membership in that Body through some other means then we must leave it up to Him to decide how that might be possible.
No one is assured of their heavenly reward until they have “finished the race” as Paul says, so it would be difficult to say who is saved here and now - likewise no one should be assumed as destined for hell until they too have faced their Judgment.
Thomas
