Many people use the expression "Jesus is Lord". They understand the use of that phrase as proof their Christianity or of another person’s Christianity if he uses that phrase. It "proves" they are a Christian.
Yet what is more important is that he really treats Jesus as Lord in his life. Does that person actually control his actions and thinking according to what Jesus prescribes? If he does not, all he is showing is he is merely capable of voicing the phrase. The phrase is meaningful if he says the phrase because, in fact, Jesus tells him what to think, where to go, who to see, what to say, what to buy.
The phrase "Jesus is Lord" is not like a magic word such as "abracadabra". The voicing of the phrase does not cause unseen events and conditions to be true and does not show they are true. If one voices the phrase this does not necessarily demonstrate he is saved or that Jesus is really the lord of his life.
