"Hey! I was reading my Bible the other night and came across Psalm 139:8, 'If I ascend into heaven, you are there. If I make my bed in hell, behold, you are there.' But isn't hell supposed to be void or anything good or God-related?"
To properly interpret this verse, we must understand that Psalms is a poetic book. In ancient Hebrew poetry, writers often used two pairs of opposites to illustrate a point. For example, in this verse, heaven and hell (the Hebrew word is שְׁאוֹל or "Sheol") are paired together. If you read the entire passage (i.e. Psalm 139:1-12), what the author is saying is there is nowhere in the universe that God will not be present to guide the believer (v. 7-10) and nowhere too dark for God to see him (v. 11-12). This includes everything in between heaven and hell.
Another way of understanding this verse is to understand that the word for hell here, "Sheol" has multiple meanings. According to The New Bible Dictionary (3rd ed.):
Sheol was below the surface of the earth (Ezk. 31:15, 17; Ps. 86:13), a place of dust (Jb. 17:16), darkness (Jb. 10:21), silence (Ps. 94:17) and forgetfulness (Ps. 88:12). Sometimes the distinctions of earthly life are pictured as continuing in Sheol (Is. 14:9; Ezk. 32:27), but always it is a place of weakness and joylessness.
What Psalm 139:8 is saying then is that God knows our activities, words and thoughts even if we are in the worst possible situations and places of weakness and joylessness. It does not mean that God's presence is in hell. In fact, the New Testament tells us that God's wrath remains on people while they are in hell (John 3:36). Read this article to find out more. The author answers the question, "What is God's relationship with people who are in hell?"
[Answered by Pastor HM]