How does one know if he or she is maturing in the Lord? 

This article concerns believing Christians only. It’s not written for non-Christians. Non-Christians reading this should stop now and trust Jesus Christ alone as your personal Saviour. Christ died for your sins, He was buried, and He rose again the third day (1 Cor. 15:3-4). God wants to see lost people trust His Son right now, trusting Him exclusively, without relying upon any manmade system or church membership, rituals or rites. One cannot grow in the Lord or even perceive the truth of the Bible if they are not first saved, regenerated by Christ’s indwelling life! Once they’ve trusted Christ, then they can proceed to the counsel found herein.

Wherever you are in your Christian life right now—whether you trusted Christ a few seconds, days, or weeks ago, or you trusted Christ several decades ago—you have much more learning to do in the Bible as “the word of God.”

Furthermore, just because someone has been a Christian for 50 years does not necessarily mean they are mature in the Scriptures. In fact, if much or all of that time was spent under denominational teaching, it’s extremely unlikely that he or she is mature in the Bible.