Do not be conformed to this world,
but be transformed by the renewal of your mind,
that by testing you may discern what is the will of God,
what is good and acceptable and perfect.
If you think that in the moment you got born again everything was settled and you don't have to do anything from now on anymore, then understand that only your Spirit got born again, but it is up to you now, to also train your soul and your body and to renew them with the word of God.
Without renewal you still have the mind and the way of acting of this world (that doesn't know God) and will never live in harmony with yourself, because your Spirit is of God, but your soul and your body are still operating like this world.
A natural mind (understanding, way of thinking,…) is a way of thinking that developed by close observation and studying of this worlds system, and therefore they see Gods spiritual laws and Gods way of thinking as foolishness, because it takes a renewed mind to fully comprehend them.
That natural mind holds you back from taking hold of Gods word and even though your Spirit understands it, your thinking and your acting will suppress your Spirit and therefore you won't be able to see Gods words acting in your life.
But if you are smart, you will renew your mind by taking Gods word and being led by His Spirit, so that He can teach you what is good, acceptable and perfect in His eyes.
Gods word has the power to renew your soul and your body, and if you take the time to be taught by His word, then you won't be a split personality any longer, because your Spirit, your body and your soul will live as one and you will walk in full manifestation of the power and favor of God!
You are a spirit that possesses a soul and a body!
Your spirit got born again the day you made Jesus Lord of your life, but it’s now up to you to transform your soul and your body to Gods way of doing things.
Your soul and your body need to be trained by Gods word, to be quick to see and act on what is good, acceptable and perfect, and not be misguided by this world.
That is true spiritual service which yields good fruits! (Romans 12,1-3)