A sermon will open the bible up, be based on biblical content, and enable you to see how the passage relates to God’s saving purpose in Jesus and our response. Without the Bible the sermon can’t exist.
A motivational talk will may use the Bible (or any other source) to illustrate its points and seek to bring about actions without demonstrating how they are based in God’s saving purpose in Christ. A motivational talk doesn’t need the Bible at all.
If you’re in church tomorrow, I hope you hear a sermon.
