What is salvation? Salvation at its roots means deliverance. When talking about salvation, you must ask what are we being delivered from.
Romans 6:23 For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
We are delivered from the effects of sin; we are delivered from death. Earlier in our study we looked at the effects of the fall of man. We saw that death had come into the world upon all, Romans 5:12. We need deliverance from death due to sin. Who is responsible for doling out that death? Is it sin itself, is it satan, no it is God? We are delivered from the wrath of a holy and righteous God. In general, when we are speaking of salvation in this study, we will be talking about the salvation earned by the shed blood of Christ whereby the wrath of God is satisfied toward those for whom that blood was shed. If salvation is being spoken of in another sense, then it will be pointed out in that instance.
Ephesians 1:13 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
We see here, not an alternative to the definition of salvation given above, but the other side of our salvation. There is that time when we are delivered from the wrath of God by the shed blood of our savior, and then there is that deliverance that is brought by the Spirit of God whereby we are translated from ignorance to knowledge by the revelation given by God to know our savior. Here we are delivered from the prince of the power of the air, from walking as the world does, Ephesians 2:2. We are delivered into the light of the knowledge of the gospel of God, not going about to establish our own righteousness but leaning on that righteousness that He has earned for us. We are saved from the penalty of sin, and we are saved from the life of walking in sin not knowing the grace and mercy that has been given to us. Both are separate occurrences and are important to distinguish in scripture which is being mentioned. Here in verse 16 Paul refers of the gospel of Christ. In this gospel is the power of God unto salvation. The gospel is that work that Christ has accomplished. This is the salvation that freed us from the wrath of God. It is eternal salvation. We see belief, but we do not see belief as a causal agent. We see the link between that salvation by His blood and all those saved will believe. That group of people include both Jew and Gentile. Here salvation comes first followed by belief. Paul is writing to those after the death of Christ and this would be the historical order of occurrence.
The gospel is also involved with our salvation from a life not knowing God. It is that deliverance from ignorance. The word of truth is critical to this.
James 1:18 Of his own will begat he us with the word of truth, that we should be a kind of firstfruits of his creatures.
1 Corinthians 1:21 For after that in the wisdom of God the world by wisdom knew not God, it pleased God by the foolishness of preaching to save them that believe.
Titus 3:3 For we ourselves also were sometimes foolish, disobedient, deceived, serving divers lusts and pleasures, living in malice and envy, hateful, and hating one another. 4 But after that the kindness and love of God our Saviour toward man appeared, 5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost;
What is preached? It is the gospel. The Holy Spirit in combination with the preaching of the word of truth is our salvation experience in life. That deliverance is to the knowledge of the truth.
2 Timothy 2:25 In meekness instructing those that oppose themselves; if God peradventure will give them repentance to the acknowledging of the truth;
2 Timothy 3:7 Ever learning, and never able to come to the knowledge of the truth.
We see the acknowledgment of the truth and those who cannot know the truth. Why do some come to repentance and others do not?
John 1:12 But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: 13 Which were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God.
Isaiah 55:11 So shall my word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it.
The word of God will accomplish all that it is sent forth to do. Who was the word of God? The word is Christ and He accomplished all He was sent to do. Just as He the gospel will perform that which it was intended. All this is according to the will God, not of the will of man.