Romans 12: 1 & 2

“Therefore, I urge you, brothers and sisters, in view of God’s mercy, to offer your bodies as a living sacrifice, holy and pleasing to God—this is your true and proper worship. Do not conform to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God’s will is—his good, pleasing and perfect will.”

Why does this entire process begin with “the renewing of your mind?”

Because we make decisions with our mind.  Our mind is the most powerful tool the Lord has given to us, and in order to serve and follow Christ we must have our minds renewed.