How do we know that Jesus is the name we should call upon?

The New Testament makes it clear that Jesus is the name above all names, and Acts 4:12 proclaims that there is no other name under heaven by which we must be saved. This is confirmed in Matthew 1:21, where the angel tells Joseph that Mary will bear a son named Jesus, for He will save His people from their sins. Furthermore, as seen in Isaiah 45, God reveals Himself as both just and a Savior, and in Christ, these characteristics meet perfectly. Hence, calling upon the name of Jesus encapsulates the entirety of divine revelation and salvation history, affirming for us that He is indeed the one we must rely on for salvation.