What are the important factors that actors should possess ?

Question:You should be able to let go of all of your OWN inner thoughts and really believe yourself that you are feeling what the character is feeling, if you believe, then the audience will.
You shouldn't over all feel embaraced. If you are insecure, the audience will be insecure and won't enjoy the performance, and neither will you. You need to forget that you are yourself, let go of all emotion. Hope that helps! SceneKid xox

Best Answer - Chosen by Asker: You should be able to let go of all of your OWN inner thoughts and really believe yourself that you are feeling what the character is feeling, if you believe, then the audience will.
You shouldn't over all feel embaraced. If you are insecure, the audience will be insecure and won't enjoy the performance, and neither will you. You need to forget that you are yourself, let go of all emotion. Hope that helps! SceneKid xox

Honesty. Talent. Dedication. The ability to fake sincerity.

make the audience believe

The overwhelming desire to act at any cost.

This answer will attempt to define an ACTOR, not a famous person.
Remember what it was like to learn your multiplication tables? That's a part of it - just pure work, work, work to learn the technical aspects like your LINES, where you are told to move on the stage, rehearsing rehearsing rehearsing, at the theatre and then at home, studying the character inside and out, waiting, waiting waiting while some other actor who isn't prepared holds up everything due to their selfishness at the worst possible time, usually when you are about to open the show(!) and are exhausted - BUT you keep quiet and wait some more and keep going.
You have to be willing to make a complete fool of yourself in front of your fellow actors - during workshop, class, or rehearsal, and possibly during performance. You have to be willing to step waaaaaaaaaay out of your comfort zone and push yourself beyond the limits of all that seems humanly possible. To bare yourself to an audience using your body, voice, mind and soul (your instrument) so that You and They are caught up in that incredible, magical moment called TRUTH.

To borrow from Shakespeare,
"Tis a consummation devoutly to be wished."