8:16 The parabolic sayings in verses 16–17 are difficult to interpret. Some think Jesus refers to himself as the one who lights a lamp. Others think that the emphasis is on the missionary role of the church, as in Matthew 5:16. I suggest that Luke 8:16–18 focuses on the same theme as that of verses 4–15, from a different angle. Jesus emphasizes the importance of responding rightly to the Word of the kingdom. The lamp, then, represents the Word, God’s revelation, which illumines our lives and gives us insight into God’s will and ways. Covering the lamp with a jar or putting it under a bed represent instances in which we reject the illumination of the Word. But when the lamp is placed where it belongs, such as on a stand, it sheds light. When disciples let the light shine, that light shines into the lives of others. Thus a missionary theme does surface in verse 16 (cf. 11:33), but it is not the main point of this section, as verses 17–18 show. Still, it is an important subsidiary point.

8:17–18 Verse 17 explains that the response to the Word will not be hidden. The function of light—what light does—is now explained. Light exposes what is in the darkness, and thus light reveals who we really are; on the last day, everything that is secret and hidden will be exposed and clear for all to see (cf. 12:2). No secrets will last forever. Therefore, since everything will be disclosed at the eschaton, we must truly listen to the Word of the kingdom now. Those who listen, those who obey now, will find more given to them (cf. 19:26; Prov. 1:5; 9:9). As disciples obey, they grow in knowledge and understanding. But those who do not hear rightly, those who reject the revelation, will find that even what they have is removed from them. Their understanding of truth and reality will become even dimmer.