Isaiah 18 is fulfilled in Acts 8 where we find that God will call the most unlikely people into relationship with Jesus and Holy Spirit wants to prompt you to make it happen too.
Judah is still being threatened from the North by Assyria. To stand against them with human thinking they need an alliance with someone more powerful than them – which Ethiopia to the South is happy to do. Ethiopia at the time ruled over Egypt. This chapter, whilst considered the hardest to understand is about God rejecting the Ethiopian offer of help and pointing forward to a time when Ethiopians will worship on Mount Zion (a metaphor for the Church)
Verses 1-2 speaks about the Ethiopian diplomats who have come to Hezekiah. The Ethiopians are hoping that swift messengers will be sent back from Judah to the tall and smooth skinned people to tell them Judah has aligned with Ethiopia against Assyria.
Verses 3-6 God rejects the offer of help “I will remain quiet”. God can prune the Assyrian army (v5) with no help from the Ethiopians.
Verse 7 then prophecies a time when Ethiopians will worship God. In Acts 8:26-40 The Ethiopian Eunuch was trying to worship at the temple and returning home encounter Philip and thus the good news of Christ. He responded to the Gospel and was immediately baptised going on his way rejoicing! The church in Ethiopia thrived from that point on!
What can we learn from this passage
Trust God not human alliances against more powerful enemies
The unlikeliest people can come to Christ “a people feared far and wide, an aggressive nation of strange speech”
Respond to the Spirit’s promptings to talk to people about Jesus Acts 8:29 “The Spirit told Philip, God to that chariot and stay near it”