Discernment

The ability to properly identify someone or something is an essential character trait. We call it discernment. All Christians should be discerning. In addition, all Christians should be discernible. In nature, identifying species is usually easy. For example, if an animal walks like a duck, eats like a duck, quacks like a duck, and enjoys being with other ducks, chances are it's a duck. Or if a tree produces apples, it's probably an apple tree. If it has acorns, it's probably an oak tree. You can always identify a tree by its fruit.
In the spiritual realm it's not such an easy task. The guidelines, however, are similar. One who is born of God develops the characteristics--the fruits--of God through the inner workings of the Holy Spirit in his life. That's why non-Christians look at you and me expecting to see evidence of the life of Christ in us. They have every right to do that. Do we walk "in love, as Christ has loved us?" Do we have an appetite for spiritual food? Is our speech "with grace, seasoned with salt," our "yes, yes; no, no?" Do we enjoy being around other Christians--"not forsaking the assembling of ourselves together?" Are we producing the fruit of the Spirit? If the Holy Spirit is in control of our lives, these are the traits He'll produce.
Birth determines nature. If you're a duck, waddle, quack, and eat those minnows. If you're an apple tree, bring on the MacIntosh or the Red Delicious or the Winesap. But if you're a child of God, walk, talk, and hunger after spiritual food and fellowship with other Christians.

Don't be confused with a duck.