You can study physics, math, medicine, or even theology, and become the top expert in your field, but if you do not know God, what you have learned doesn't amount to much. Knowing God personally is worth more than possessing all the knowledge in any other subject field. It is through God that you come to know the truth about this life and beyond. Also, you can only know God through the heart, so he is special. Rejoice, if you hear him calling you to know him in your heart.