How do we know preaching the gospel is necessary?

In 1 Corinthians 9:16, Paul expresses that necessity is laid upon him to preach the gospel, asserting that failing to do so would result in woe and eternal destruction. This underscores the urgency and compulsion of the gospel message for both the preacher and the hearer. The biblical basis for this necessity is corroborated by the understanding that it is through the foolishness of preaching that God has chosen to save the believers and that preaching is God's ordained means to accomplish His salvific purpose.