Hebrews 5:9 says that Jesus is "the source of eternal salvation."
I love this title for Jesus: The word “source” means the reason for something existing. The source is the place of origin. Jesus is the supplier of eternal salvation. Hebrews 12 describes Jesus as the author or founder of our faith.
Salvation from sin and an eternal relationship with God is found only in Jesus (He is the sole source). Eternal salvation is found in no other place in the entire universe. Jesus is the source, the supplier, the origin, the place where salvation is found.
And the idea of this phrase is not just that Jesus gives salvation and then goes on about His business as if salvation were a possession to be traded. Salvation is not essentially something that we possess. Salvation is essentially a person that we treasure. That Jesus is the source of eternal salvation means that we must have Him to have eternal salvation.
No one goes to Jesus for salvation and then turns away from Jesus to something else. You don’t stick salvation in a drawer and then live life any way you please. Only those who have Jesus have eternal salvation because Jesus is the source of salvation. At every point in God’s work of drawing us to Himself (justification, sanctification, and glorification), it is Jesus who is our salvation.
And don’t gloss over the word “eternal” in this title for Jesus. Jesus is not just the source of temporary salvation. Jesus is the source of everlasting salvation. For all eternity, Jesus will be the fountain of righteousness that we will drink from. If you have eternal salvation through Jesus, 50,000 years from now, you will need Jesus to be your source of salvation just as much as you need Him today.
It will always be through Jesus’ mediation that we will draw near to the throne of grace.
Who cares about temporary salvation? What good is momentary atonement? Give me eternal salvation! Give me a High Priest who is the source of salvation that will never end. Jesus is in every way a superior High Priest.