Particle electron serial communication with arduino

I have Particle electron and i am trying to make it to communicate with arduino via Tx and Rx pin of the Particle and arduino, i tried using Serial1 on particle but no result.
After that i need to make the Particle communicate with arduino via XBeeS2C…Please Help me
i have graduation project and

Thank you

As you might imagine, this is a fairly common intent and hence has been asked before.
Have you had a search in the forum?