The scriptures say that we should be transformed by the renewing of our minds (Rom 12:2). Often we think of this verse in terms of sin - that is, "train your mind to do good things and not bad things". That is a very shortsighted, defeatist way to look at it. The great battle is not learning to overcome sin, because Jesus already did that for you and gave you His divine nature. The great battle is learning how to think and behave like someone who carries that divine nature. And for many of us, that means unlearning many thought patterns and habits that we think are good and spiritual, but are actually obsolete and useless. God has already given us everything that we need for life and godliness (2 Pet 1:3), so our mission is to condition our minds to think that way, and then we can truly begin to live by faith - faith in what Jesus has done for us and not what we can earn for ourselves.