Why Do Freemasons Have Secret Handshakes and Words?

In early times like at the building of Solomon's Temple the overseer of the work would not know everyone on the job.  The worker gave the overseer a secret handshake of word so that the overseer would know how much the man should be paid.

The Secret Handshake and/or Word enabled the workers to identify others of the same degree.

This also helped protect the workers from the Church which seemed to get pleasure in Burning people at the stake if they knew something that the Church leaders did not want that poor person to know.