But how are men to call upon him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without a preacher? And how can men preach unless they are sent? As it is written, "How beautiful are the feet of those who preach good news!" But they have not all obeyed the gospel; for Isaiah says, "Lord, who has believed what he has heard from us?" So faith comes from what is heard, and what is heard comes by the preaching of Christ. Romans 10:14–17 (RSV)
Preaching is half of a pastor's call. The Holy Sacraments complete the responsibility of the pastoral office. Pastors do many other things from Sunday to Sunday; most are important to the parish's life. A faithful pastor seeks to accomplish as much as possible for the blessing of the members.
Still, if all the pastor did was to prepare and deliver solid sermons and rightly administer the Holy Sacraments, they would be fulfilling their call.
Luther was clear that proclaiming the Gospel in Word and Sacraments lay at the very heart of the Christian faith.
The pastor understands that every sermon is a matter of life and death. The pastor is keenly aware that there always be someone who is aching to hear the Gospel. Every week, someone is in desperate need of hearing that Jesus is their Savior. They need to hear that they too can be saved, their sins are forgiven, and that hope in Christ is theirs as well.
The pastor gives hours in preparation for preaching. Their fervent prayer is the gift to make sense, to let Jesus shine through their stumbling words. Though they may feel the burden of preaching, it is offset by the joy that comes when our Risen is proclaimed.