"For every one that useth milk is unskillul in the word of righteousness: for he is a babe. But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil. (Heb. 5:13-14)
Have you ever wondered what the Bible means by the "milk" and "meat" of the Word? Or who God would categorize as being a spiritual "babe," as opposed to someone who wears the distinction of "full age"? One might be tempted to see the latter epitomized by someone who can explain the intricacies of the Old Testament Tabernacle furnishings and practices, or perhaps expound upon the imagery of the book of Revelation; but according to this verse, Spiritual grown-ups are those able to discern between good and evil. And frankly, there doesn’t seem to be all that many running around, who fall into this category.
Strangely enough, the discipline that will bring one to this favorable plateau in his or her Christian life is not how much Bible is read, or how much prayer is offered, but, instead, how well disciplined are the senses. That's an eye-opener, isn't it? As important as our daily contact with God through prayer and Bible reading is, we can allow intemperate senses to hinder their effectiveness in our lives. My husband often says that a simple, definite "No!" has done as much or more to give him victory over sin than all the Bible verses He could—and in many cases, did—quote.
We cannot deny our senses, nor would God have us to, for they are a gift from Him. But, left to themselves, they can fool us, at best, or destroy us, at worst. They simply cannot be counted on to tell us what is good and evil, unless they have been "exercised unto godliness" (1 Tim.4:7). And, don't forget; the sharpest tool in the chest when it comes to discerning good and evil is a sword (Heb.4:12).
If you are still making decisions based on how things look, or how you feel, you're still a Spiritual baby, no matter how long you've been saved or how much Bible you can quote.