Have you heard of a saying “if you keep doing the same thing, don’t expect different results”. This means if the input is the same, the method is the same, then the output will be the same. To get different results, either the input or the method must change. Now, for this to happen, you need to change the way you think. If your thinking is different, your way of doing things will equally be different, the way you behave or react towards anything, will also be changed by your thinking differently. The same thing applies to being a born again Christian.
2 Corinthians 5:17 (ESVST)
Therefore, if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come.
When you were born again, you became a new creation. That means you got rid of your old self and put on a new self. This must include changing the way you think as well, so that your new thinking can be in line with the new you. There is no point in being a new creation, if you still think the same way you did while you were still the old you. Your thinking must change.
Romans 12:2 (AMP)
Do not be conformed to this world (this age), [fashioned after and adapted to its external, superficial customs], but be transformed (changed) by the [entire] renewal of your mind [by its new ideals and its new attitude], so that you may prove [for yourselves] what is the good and acceptable and perfect will of God, even the thing which is good and acceptable and perfect [in His sight for you].
Verse 2 above could not be clearer. You need to be transformed (completely changed), 100% changed. This you can achieve only by the ENTIRE renewal of your mind. Your mind needs to change. Your way of thinking needs to change. You simply need to look at things differently and in this way, your behaviour will also be affected. The way you think, dictates how you will behave.
Verse 2 above says, if your mind has been renewed, you will be able to prove or see for yourself what is the good and acceptable and perfect will of God. You cannot know what the will of God is or what is acceptable and good in the eyes of God, if you don’t renew your mind.
To be a new creation is to put on a new self, to put on a new self, is to be completely transformed, to be completely transformed means, to completely renew your mind and only when your mind is renewed can you know what the will of God is and what is acceptable and good in his sight.
Ephesians 4:22-24 (ESVST)
to put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires, 23 and to be renewed in the spirit of your minds, 24 and to put on the new self, created after the likeness of God in true righteousness and holiness.
So, you have to renew your mind in order to put on the new self. There is no point in putting on those new fancy clothes if you have not washed your body. The clothes will simply be dirty because you are dirty as well. Likewise, to put on a new self without your mind being renewed is pointless.
What does it mean and how does one renew his mind?
Colossians 3:9-10 (ESVST)
Do not lie to one another, seeing that you have put off the old self with its practices 10 and have put on the new self, which is being renewed in knowledge after the image of its creator.
The word mind is a Greek word “nous” which also means “understanding”. Therefore, renewal of the mind also means being renewed in the knowledge. This means having new knowledge that you never had before. This means ensuring that you acquire this new knowledge but, this is not just any knowledge, this is the knowledge after the image of the creator. What does this mean?
Colossians 3:10 (AMP)
And have clothed yourselves with the new [spiritual self], which is [ever in the process of being] renewed and remolded into [fuller and more perfect knowledge upon] knowledge after the image (the likeness) of Him Who created it.
Therefore, this means you have to acquire the knowledge, the same knowledge of Him who created it. This means you need to acquire the knowledge of God. How do we then acquire the knowledge of God? The only place to find it is in the bible. The bible is the word of God and was written by God using holy man.
2 Peter 1:20-21 (ESVST)
knowing this first of all, that no prophecy of Scripture comes from someone’s own interpretation. 21 For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit.
So, if you want to have the knowledge of God, read His word.
2 Timothy 3:16-17 (ESVST)
All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, 17 that the man of God may be complete, equipped for every good work.
To be a new creation is to put on a new self, to put on a new self, is to be completely transformed, to be completely transformed means, to completely renew your mind, to renew your mind means to know the word of God, to know the word of God means to read the bible and only when your mind is renewed can you know what the will of God is and what is acceptable and good in his sight.