Luke 8:16-18 Take Heed How You Hear And See.
When Jesus said, “He who has ears to hear let him hear,” he was saying the same thing which He is saying with this parable when He says, “Take heed how you hear.” (v. 18 Cf. Mk. 4:21-23) The purpose of a lamp is to light up an area so that one can see where to walk and where not to walk, and enables one to actually function for all else as well (v. 16 Cf. Mt. 5:15; Mk. 4:21). In this context, following the parable of the sower, and the importance of bearing fruit, we are given light in this life to live in such a way that in the next life we do not enter into an unfavourable judgment (v. 17 Cf. Mt. 10:26; Lk. 12:2; I Cor. 4:5; II Cor. 5:10; Eccl. 12:14). The lamp of the body is the eye (11:33-36), so that those who refuse to look at themselves truthfully are willfully blind.
Anyone who hears but does not do, is like a person who has a lamp but puts it under something so that it does not expose their thoughts or deeds. Even where the light does shine, the brighter or less hidden the light, the more it will expose. Like the seed sown, only the light that is not taken by the devil, shrouded out by a hard heart, or dimmed by the cares of the world, can give full and complete knowledge or revelation. As with the cultivation of the seed, the more one receives the light the brighter it becomes and, “to him more will be given.” (v. 18) This is seen in the destiny of the unprofitable servant (Mt. 25:29 Cf. 13:12). However, Luke adds an important caveat-some only “seem” to have their eyes open with a knowledge of the word (Cf. I Jn. 2:19). By one’s fruit, one is known.