Question: Why is the Son of God called “Jesus,” that is, “Savior”?
11 He is the stone which was rejected by you, the builders, but which became the chief corner stone. 12 And there is salvation in no one else; for there is no other name under heaven that has been given among men by which we must be saved.” Acts 4:11, 12
23 The former priests, on the one hand, existed in greater numbers because they were prevented by death from continuing, 24 but Jesus, on the other hand, because He continues forever, holds His priesthood permanently. 25 Therefore He is able also to save forever those who draw near to God through Him, since He always lives to make intercession for them. Hebrews 7:23-25
Question: What benefit do we receive from the fact that the Father wished His Son be called “Jesus,” that is, “Savior?”
Answer: The God of truth, who cannot lie, commanded by the angel that His Son born in the flesh be called “Jesus,” that is, “Savior.” Therefore, I am certain that in our bodies and souls He saves both me and all who trust in Him, and out of such faith I call upon Him. On the other hand, I also know that those in need who look for help and comfort in their own merits, in the saints, or in other creatures in whom they place their hope and trust, by their deeds deny all but the mere name of Jesus the only Savior, even though they boast of being His.
For either Jesus is not a perfect Savior, or those who in full trust accept this Jesus must have in Him all they need for their salvation. Therefore, as often as I hear the name Jesus, I shall remember the full salvation that is promised to me and all believers in the name Jesus. The angel himself explained the name Jesus by the promise contained in it, when he said, “For He will save His people from their sins.” (Matthew 1:21)
Hence I know that I, who believe in Him, who belong to His people, and thus am baptized as a member of Christ and His people — I have been saved from my sins by His merit, so that they are pardoned forever. I also know that by His power He will rid me of the remaining sin that afflicts me. And when He appears for our redemption, He will completely reveal in me the eternal life He has begun in me by His Spirit. Thus I believe that it is also for my sake that the Son of God bears this glorious name Jesus, or Savior, so that He might demonstrate in reality and deed the truth of His name in my and other believer’s salvation. Faithful is He who bears this glorious name Jesus: He who has promised what His name claims will also carry out this promise.
Caspar Olevianus, A Firm Foundation, p. 35