Your Heart
Esoterically, the heart is the center of feeling and the source of the subconscious.
Proverbs 4:23 (King James Version)
23Keep thy heart with all diligence; for out of it are the issues of life.
John 14:1
Let not your heart be troubled: ye believe in God, believe also in me.
Look at your circumstances, your surroudings, friends health and your decisions and you can determine what ideas and thought you have allowed to enter into your heart. Are they thoughts of doubt , fear, sickness, disease and poverty? or are they thoughts of faith, courage, peace, health and prosperity? If not the latter, then change your thoughts.