Some Sundays, we will answer this question with a loud "YES"! Hopefully, on other days, we will hear God's voice - an encouragement or a challenge - something to equip us for the rest of the week.
But, what if you are the preacher wondering if you are wasting your time? Unresponsive congregations, little change in people's lives, lack of inspiration in the study.... any of these things might make us weary or cynical as wel prepare our sermon. Bluntly, we probably are wasting our time (and that of our congregations!) unless our talks are....
Biblical - The Bible is still a miracle book and our final authority. Preaching which doesn't take seriously a biblical verse or passage doesn't deserve to be called preaching. God has promised to honour His Word not our good ideas!
Spiritual - The sermon is not a lecture. However many hundreds of sermons we may have preached, each one must be set on fire through prayer with the power of the Holy Spirit.
Applied - What are people supposed to DO as a result of the message? How should they change their thinking ab out themselves, their families and the world?
Entertaining - Even if we do all of the above, sermons will be ineffective if the congregation is asleep! We live in a very visual and fast-paced world. Boredom is an ever-present danger for contemporary congregations. Most of us, as preachers, could do with being briefer, more relevant and introducing variety into our style and approach. A dull sermon is a contradiction in terms!
May God help every preacher to embrace these princicples in Sunday teaching. If you're not the preacher, pray for yours as week by week they commit to this very challenging (often thankless!) task.