Why should we confess that Jesus Christ is Lord?

Wherefore God also hath highly exalted him, and given him a name which is above every name: That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; And that every tongue should confess that Jesus Christ is LORD, to the glory of God the Father.

Philippians 2:9-11

It is simple. The name of Jesus is above all other names on Earth and one day, all will know who their creator is. Some people will find out the hard way.