Matthew 18:1-4 (ESV)
At that time the disciples came to Jesus, saying, “Who is the greatest in the kingdom of heaven?” 2 And calling to him a child, he put him in the midst of them 3 and said, “Truly, I say to you, unless you turn and become like children, you will never enter the kingdom of heaven. 4 Whoever humbles himself like this child is the greatest in the kingdom of heaven.
Spiritual maturity is the result of dependence on Christ. Dependence on Christ is the result of a humble and trusting heart.
Mark 9:33-34 (ESV)
33 And they came to Capernaum. And when he was in the house he asked them, “What were you discussing on the way?” 34 But they kept silent, for on the way they had argued with one another about who was the greatest.
Matthew 20:20-21 (ESV)
20 Then the mother of the sons of Zebedee came up to him with her sons, and kneeling before him she asked him for something. 21 And he said to her, “What do you want? ”She said to him, “Say that these two sons of mine are to sit, one at your right hand and one at your left, in your kingdom.”
Challenge #1: Turn from worldly thinking.
Challenge #2: Humble yourself like a child.
Humility is not thinking less of yourself. It is thinking of yourself less and recognizing your continual need for God's grace.
John 15:4-5 (ESV)
4 Abide in me, and I in you. As the branch cannot bear fruit by itself, unless it abides in the vine, neither can you, unless you abide in me. 5 I am the vine; you are the branches. Whoever abides in me and I in him, he it is that bears much fruit, for apart from me you can do nothing.
Challenge #3: Depend on Christ daily.
Challenge #4: Grow into spiritual maturity.
Philippians 3:8-12 (ESV)
8 Indeed, I count everything as loss because of the surpassing worth of knowing Christ Jesus my Lord. For his sake I have suffered the loss of all things and count them as rubbish, in order that I may gain Christ 9 and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith— 10 that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death, 11 that by any means possible I may attain the resurrection from the dead.
12 Not that I have already obtained this or am already perfect, but I press on to make it my own, because Christ Jesus has made me his own.