search one's heart
search one's soul

Casey is not the only one who says the Nets need to search their soul.

She turned very slowly, and I felt her gaze burning into me, searching my soul.

I searched my soul for fear and found it not.

"So I searched my soul and decided we would decorate the house."

I started, and got the uncanny feeling that this man was searching my soul.

He didn't say anything for a long time, searching her face as she searched his soul.

"I kept searching my soul and asking myself what was so important about just six bones," she said.

Gazing at her as if he knew she searched his soul.

He could still search his soul over which path to follow.

"Sometimes it amounts to searching your soul before you can answer," he said.