Prepare the marinade. Add all ingredients for the marinade (olive oil, garlic, lemon juice, lemon zest, fresh thyme, fresh oregano, fresh rosemary, fresh parsley, salt, and black pepper)to a large shallow mixing bowl. Mix well to combine.
Marinate the chicken. Add the chicken breasts to the marinade and mix well to coat in the marinade. Allow chicken to marinate for at least 30 minutes to two hours.
Prepare the grill. Clean grill grates and lightly oil with vegetable oil or cooking spray. Set grill to medium-high heat.
Grill the chicken. Remove the chicken from the marinade and place directly on the grill. Discard remaining marinade. Cover the grill and allow chicken to cook for approximately 5 minutes before reducing heat to medium. Allow chicken to cook for an additional 2 minutes, then use tongs to flip each breast over. Grill for an additional 5-7 minutes (or longer), or until the thickest part of your chicken registers 160 degrees F. with a digital meat thermometer.
Allow chicken to rest. Remove chicken breasts from the grill and set aside to a clean plate. Tent with foil and allow to rest for 5 minutes before slicing.