trying to update the guiText.text component only when required

im getting the following error when im tyring to call a very specific function only when required so that i can update the HUD rather then doing a call every frame

Player.cs(61,47) error CS0120: An object reference is required to access non-static member `UnityEngine.Component.guiText'

 player player1 = new player();

 void updateHUD() {
     this.guiText.text = "Health: " + player.CalculatePlayerHealth (0,0);
 }

if anyone can fix my code id be greatful and ive looked everywhere for an answer...