The very definition of Christian Maturity might be a strong title for a blog post. I intend it as such. I don't know too many people who talk about the goal, the aim, the target. I suggest that no better understanding of Christian maturity can be found in the NT than Ephesians 4.13.
In the ESV, it reads, "...until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ."
Want to know the goal for Christian maturity? The measure of the stature of the fullness of Christ.
There it is. Until we are all grown up like Jesus.
We believe like He believed.
We think like He thought.
We feel like He felt.
We act like He acted.
We relate like He related.
But it's more than that...
We believe like He believes (present tense - because Jesus does believe and see, knowing what is truly real and what is faux reality).
We think like He thinks about current situations.
We feel like He feels about circumstances that we encounter.
We act as He is acting, or at the very least would act if He were among us.
We relate like He relates to the people around us.
In short: Christian maturity is living as Jesus would live if He were in our shoes. Or, the measure of the stature of the fullness of Christ.
But that's just me thinking thoughts...