Why were Christians in the second and third centuries sent to their deaths in the arena? Not because they were saying, "Jesus is God." The Romans would have smiled and said, "Fine. We'll add him to our list." But when these Christians heard the term "Lord" (kurios/dominus) applied to the Roman Caesar, they said, "Awfully sorry, but I'm afraid he's not. There is only one Lord, and his name is Jesus Christ." For that, they were sent to their deaths.
The hallmark of authentic Christian spirituality is when a person proclaims from the heart, not "Caesar is Lord," but "Jesus is Lord" (1 Cor. 12:1-3). He is the Lord of the Old Testament who has come to us with all of his divine authority. He is the Lord of all creation, and Paul insists that anything that contradicts this claim is counterfeit.
We need to be warned about trying to have a spirituality without Jesus' authority. He made all things, and all things are made for his glory. The hallmark of authentic Christianity is that this lordship of Jesus Christ is worked out in our lives, even in our titles (Jesus alone is the church's Senior Pastor).