How do we know that God saves through preaching?

Romans 10:14-15 articulates the necessity of preaching for salvation, stating that one cannot call on Christ without first believing, and believing requires hearing, which cannot occur without a preacher being sent. This text underscores that God has ordained the use of preaching the gospel as the means through which He saves those who believe. It highlights the importance of divine calling in the work of evangelism and ecclesiology, affirming that salvation is a sovereign work initiated and sustained by God through the means of faithful preaching.