In a large bowl, mix together garlic, soy sauce, olive oil, honey, and red pepper flakes. (You can also mix the marinade in a ziploc or stasher bag.)

Add chicken to bowl and marinate for at least 20 minutes, or up to overnight. Stir chicken or flip bag to distribute marinade occasionally.

Remove chicken from refrigerator to come to room temperature and preheat 2 burners on the grill to medium high, about 375 degrees F.

Grill on direct heat, skin side down for 6 minutes, flip and grill for another 6 minutes, then move to indirect heat and cover. Let cook until chicken thighs reach an internal temperature of 180-185 degrees F. Thighs usually take about 20-25 minutes total, but it will really depend on the size and heat of your grill. 

Let rest for at least 5-10 minutes before serving.