How tempting it can be to think that Christian maturity lies in knowledge, especially the right knowledge - knowing the right things, right doctrine. I should know. That's been the story of my life. Learn, learn, learn. Study, study, study. But Christian maturity isn't all about knowing all the ins and outs of theology or a particular branch of theology. Nor is it in possessing certain skills or having experience.
None of this is to discount the importance of doctrine or knowledge. After all, Paul tells the church at Collosae, "Him we proclaim, warning everyone and teaching everyone with all wisdom, that we may present everyone mature in Christ." And in Hebrews it says, "Therefore let us leave the elementary doctrine of Christ and go on to maturity..."
Paul Tripp, in "Dangerous Calling" says,
It is clear from examining Scripture that...fruitfulness or failure is seldom only about knowledge, strategy, skill, and experience.
Romans 4 tells us something very significant about Abrahams' heart. Think about it: when you and I are called by God to wait for an extended period as Abraham was, often for us our story of waiting is a chronicle of ever-weakening faith. The longer we have time to think about what we are waiting for, the longer we have time to consider how we have no ability to deliver it; and the longer we have to let ourselves wonder why we have been selected to wait, the more our faith weakens. But not so with Abraham. We're told in this passage that during this time of protracted waiting, his faith actually grew stronger, and the passage tells us why. Rather than meditating on the impossibility of his situation, Abraham meditated on the power and the character of the One who had made the promise. The more Abraham let his heart bask in the glory of God, the more convinced he became that he was in good hands. Rather than a cycle of discouragement, and hopelessness, Abraham's story was one of encouragement and hope. Why? Because he meditated on the right thing."
(C.f. Rom 4:18-21)
We could walk through the Bible looking at different decision points God's people had. What always made the difference was the condition of the individual's heart. It is "the inescapable X-factor" as Tripp puts it.