Salvation Outside The Church? -- Impossible
That Jesus Christ is the Savior of the world is a fact that is widely believed. Before Jesus was born, an angel appeared to Joseph in a dream, telling him of Mary's child, saying, "and thou shalt call his name Jesus, for he shall save his people from their sins." (Matt. 1:21)
In the midst of his ministry, Jesus himself declared, "The Son of man came to seek and to save that which was lost." (Lk. 19:10)
After the death and resurrection of Christ, John said, "And we have beheld and bear witness that the Father hath sent the Son to be the Savior of the world." (I John 4:14)
From these three statements we see that (1) before his coming, (2) during his ministry, and (3) after his leaving of the world, Jesus was declared to be the Savior of men.
Salvation Only In Christ
Christ being the Savior of the world, we know that salvation is in him. Man cannot be saved until his sins are forgiven. Sins are not forgiven until one has been redeemed by the blood of Christ; for we read, "the blood of Jesus his Son cleanseth us from all sin." (I John 1:7) Also Paul declares that we have "our redemption through his blood." (Eph. 1:7)
The blood of Christ is connected with the body of Christ. Is not that only according to nature? Could the body of Christ give and impart life apart from his blood? Can any human body continue to possess life apart from its blood? The church of the Lord has been purchased with the blood of Jesus. (Acts 20:28) Now we have this connection: one is saved in Christ; one is saved by the blood; the blood is in the body. Hence, no person can have the one without the other. This agrees with Paul's statement, "Therefore, I endure all things for the elect's sake that they may also obtain the salvation which is in Christ Jesus with eternal glory." (II Tim. 2:10)
Salvation Only In The Church
Someone may say, I grant you all that; but still what has that to do with the church? Let us apply the laws of logic or reason; can you speak of a man without speaking of his person? Can you speak of one's person without speaking of his body? Suppose a physician, upon examination of a patient, discovers the patient has been shot with a bullet. He exclaims, "I found a bullet in this person." Would he have meant that the bullet was found in the person's body? What else could he have meant? How could a bullet be in a person without being in his body? When we speak of any member of the human body, we are speaking of the body of the person who possesses the member. We cannot speak of a man's head, for example, without speaking of the man. We cannot speak of being in Christ without speaking of the body of Christ.
No one could hope for heaven without the spiritual blessings which are so essential to our salvation. Yet Paul declares that all spiritual blessings are "in Christ". (Eph. 1:3) The temporal blessings may be enjoyed even by infidels, atheists, and rebellious and scornful men. But blessings of a spiritual nature are reserved for those who are in Christ, in his body, in his church. For, in this sense, Christ, his body, and the church are identical.
The Church Is The Kingdom
John speaks of the church as a kingdom. (Rev. 1:4,6,9) If there is only one church (Eph. 4:4,5), then there must be only one religious kingdom. Whatever may be said in the New Testament regarding the kingdom may be said regarding the church. Consider:
First. Paul said the Lord, "delivered us out of the power of darkness and translated us into the kingdom of the Son of his love." (Col. 1:13) If one is in the kingdom of Christ, he is out of the kingdom of darkness; if he is not in the kingdom of Christ, he is still in the kingdom of darkness.
Second. Concerning the Lord's Supper, Christ said, "I shall not drink henceforth of this fruit of the vine, until that day when I drink it new with you in my Father's kingdom." (Matt. 26:29) When we partake of the Lord's Supper, we proclaim "his death". (I Cor. 11:26) Now since the Supper is in the kingdom, how can anyone partake of it and declare the death of Jesus until he is in the kingdom?
Third. Jesus said, "Seek ye first the kingdom of God and his righteousness". (Matt. 6:33) Does not the word "seek" carry with it the idea of "earnestly looking for" or "desiring"? But why should Jesus make a statement of that kind if one does not have to be a member of the kingdom, or church? What shall we do with the kingdom (and righteousness) of God when we find it? Does it not stand to reason that upon discovery of the "righteousness" of God, we discover also the kingdom of God, even the Father." (I Cor. 15:24) If at the end of time the kingdom of Christ will be delivered up to God, how can he who is not in the kingdom be delivered to God? How can anyone hope to have God as king without being in the kingdom over which the Son is now ruler, and over which God is to reign eternally? One can have no hope of salvation outside the church!