If God has perfect knowledge and is all knowing, why would he choose to limit his power?

I'm a believer of God and worship Christ Jesus as my savior. I have been engaged in a discussion in a forum about the existence of God. I brought up the point that God may have perfect knowledge and is all knowing, but God limits his ability. The argument that was brought up is, if God is omnipotent, why would he limit his powers? Is there scripture or any text that supports the idea that God limits his power? What would your argument be?