Can a slave and their master worship the same God?

The original-language words rendered “slave” or “servant” are not limited in their application to persons owned by others. Though not a worshiper of the true God, who's name is (Jehovah), one who performed a service that was in harmony with the divine will could be spoken of as God’s servant, an example being King Nebuchadnezzar.—Jer 27:6. Galatians 3:28
Short answer Yes. For more ref info please research jw.org