5 Tips for Responding to a Bad Sermon
#1: Give them the benefit of the doubt. 1 Cor. 13 says love "hopes all things, believes all things." That is, assume they really did give their best effort and really did want to encourage, exhort, and challenge you that day. They didn't mean to hurt you or disappoint you. It's just that they are human and will not walk on water every Sunday.
#2: Don't share your opinion with others. If you didn't like the sermon, keep it to yourself. Even if someone asks, be careful not to speak negatively of a brother or sister in Christ. One negative word from you could start a fire of destruction in a hearer's life and even worse it could get back to the preacher and destroy their soul.
#3: Give them feedback. First, give yourself and the preacher 24-48 hours (certainly not that very Sunday morning). If you still think there are 2-3 things (and probably no more than 2-3) that need to be addressed, call them up. Try and offer a few words of encouragement on what they did well. And yet, don't be shy to help a growing preacher (and we're all growing whether we've been at it 5 years of 35 years) mature in their ability to use God's Word. (Just think how cool it was that Priscilla and Aquila offered feedback to the incomplete, but growing preacher named Apollos, see Acts 18.)
#4: Pray for the preacher. In former years when I wasn't the regular preaching pastor, I often sat in my seat as a critical observer. I always thought they could do better, and I sometimes wished I could be elsewhere...until I saw this as selfishness and sin. I confessed my sin (often), and committed (and recommitted) to pray for the preacher that they would feed me and the other sheep. When I prayed, two things happened. (1) Their preaching came with more power, and (2) I could grow in my proper place of submission.
#5: Believe in the power of the Gospel. We know from Romans 1:16 that the good news of Jesus Christ has the power to save. This message is potent. Its potency is not dependent on the eloquence of the preacher. Its potency is not subject to great application points. Pray for Gospel-preaching preachers not merely great preaching preachers. The power lies in the Gospel, not in the human instrument that conveys the message.