So then I turned from the One who loved me the most and severed the last tie of my salvation. I promise you that it was not the most happy time in my life. It was the darkest. And the most hurtful. God left me alone pretty much.

Jephthah knows about God, and his knowledge about God is correct, but Jephthah doesn't know God! Think of this! He is facing the greatest crisis of his life, and he doesn't know God! He only knows about Him.