Final answer:
The highly successful Assemblies of God radio outreach that was broadcast for forty-two years is Revivaltime.
Step-by-step explanation:
The highly successful Assemblies of God radio outreach that was broadcast for forty-two years is Revivaltime. Revivaltime was a radio program that featured sermons, music, and other content related to the Assemblies of God Christian denomination. It played a significant role in spreading the message of the Assemblies of God and attracting a large audience of loyal listeners.