I recently quoted a scripture to someone. The one that says let this mind be in you that was in Jesus Christ (Philippians 2:5). He politely got back to me and basically said, “No thanks, I already have my own mind." This person happens to be an atheist. After reflection on our short dialog it occurs to me that he would hear this as an exhortation to replace his mind with the mind of Jesus Christ and therefore give up his individuality.

That’s not what I think God is up to. If so then why would He create a vast universe filled with diversity, complexity and uniqueness?

I think the idea is that we allow our own minds to be given direction, focus and the influence of our Creator (the greatest mind in the universe) through His presence in us through Jesus Christ. Our mind is plastic and malleable. It will grow and develop into a unique creation based on the influences we expose it to. We like to think that we are the best judge of what influences to expose our minds to. We might choose the musings of Einstein, the music of John Lennon, or the experiences of mountain climbing. Some might seek to develop a serious rational-type mindset, others a carefree or fun-loving way of thinking. Plus, we are exposed to plenty of influences against our wills!

Whatever eclectic mix we end up with, that mix will become us. But we do have some measure of control over how these experiences and influences come into our mind and especially how we process them once they enter into our thoughts. God, your Creator, offers to share with you His own way of thinking--the mind of Christ. Other English translations of Philippians 2:5 say something like “have this way of thinking in you.” I checked the definitions in the original language (Greek), and this way of translating the verse seems true to the meaning originally intended.

God's purpose is not to supply a replacement for the mind you have, but to give you a new way of looking at the world you experience. So let the mind of Christ become part of the mix. How big a part of the mix will that be? It depends on you.

The place to start is to get to know Him through exposure to His written Word. You might like to take a look at this handy study aid: How to Understand the Bible.