Only God can save
I guess Gideon didn't save anyone. Nor did Othniel (Judges 3:9). And Moses wasn't involved in the Israelites being saved from Egypt (Exodus 14:30). And what does one make of the “saviours” God gives in Nehemiah 7:27 and Obadiah 1:21? As in all these past examples, it would make sense for God to save His people from their sins through another person who is not Himself. It is God who was sinned against, and it's God's wrath that needs to be propitiated. If the Son and the Holy Spirit are also God then why wasn't their wrath propitiated as well as the Father's? And if that is what happened (although scripture nowhere hints at such a thing), how could Jesus exhaust His own wrath upon Himself?