1 Samuel 28:16-18 (KJV)
16 Then said Samuel, Wherefore then dost thou ask of me, seeing the Lord is departed from thee, and is become thine enemy?
17 And the Lord hath done to him, as he spake by me: for the Lord hath rent the kingdom out of thine hand, and given it to thy neighbour, even to David:
18 Because thou obeyedst not the voice of the Lord, nor executedst his fierce wrath upon Amalek, therefore hath the Lord done this thing unto thee this day.
Obey The Voice Of The Lord
Please know that when we stop listening to God, He also stops working in our lives. Therefore, the enemy has access to our lives, in order to hurt us physically and spiritually.