God and Reason

Here's another question--what place does the mind (logic) have in a Christian's walk? You have some verses that say,

"Jesus replied, "Love the Lord your God with all you're heart and with all your soul and with all your mind." (Matthew 22:37)

And then you have another verse, that says,

"Trust in the Lord with all your heart,
lean not on your own understanding."
(Proverbs 3:5)

Then you'll have another verse that says,

"Do not be conformed to this present world but be transformed by the renewing of your mind, so that you may test and approve what is the will of God..."
(Romans 12:2)

Whoa--wait a minute--I thought it said we weren't supposed to rely on our own understanding, and yet it says we are to test and approve what is the will of God. What does that mean?

(Same rules apply--check out question "God's Will")