Differences are often a result of more style than obedience! Some football and basketball coaches are in the face of their athletes. Others are not. Who is better? Which one is coaching? Who would you prefer to play for? Caution here, both styles are winners!
Deeper still is the difference between Greek and Hebrew thought. Greeks were logical in their thinking, thus the logical letters of Paul as is Romans. But Jesus taught in stories, the Prodigal son, the wheat and the tares, the Good Samaritan. Who was more spiritually mature, Jesus or Paul? Jesus was straight and in the face of some… the Pharisees who claimed spirituality but weren't. To the woman caught in adultery he was forgiving and instructed her to go and sin no more. Truth with forgiveness!
We skew differences when we use tags like "spiritual" or "mature" when they may very well be stylistic differences. The beauty of the Lord of history is that He has intentionally included all types of writing styles in the scripture. And all of the Bible is scripture, the prose and the line by line.
You will have differences with others who follow Jesus. But the caution is to not place a tag of spirituality when the difference may be a preference!