Many people have heard of the TV show "The Twilight Zone" which was popular in the 1960s. Many famous actors did guest appearances on this show. As the introduction explained, the stories were about strange events that occurred in areas that bordered reality and fantasy/science fiction. Twilight is that time of day between day and night. It is not quite either one, yet it is a little of both. There is still some light, but it is fading as darkness comes. It is the zone where the border between two states is not clear and is in transition. There is enough light to see somewhat, but not with full clarity.
Revelation 8:12 speaks of a time when a third of the sun, moon, and stars are smitten so they do not fully shine. There was a blind man in Bethsaida who was healed by Jesus (Mark 8:22-26). After the Lord touched him, He asked if he could see. He said he saw men as trees walking. Jesus touched him again and he saw clearly. There is a spiritual twilight zone that too many people are in. They have been touched by the Lord and they see somewhat. They are not totally blind and in darkness, but neither do they see all things clearly. This is true to some degree of all men. Paul said it is like we are looking at eternity through a piece of smoked glass (1Cor 13:12), but someday we will see all. Mirrors were not originally made of glass, but metal shined to give reflection. The word darkly in this verse is the Greek word ainigma, which is where we get the word enigma. This means it is obscure. John said we don't know what we will be like in eternity but we will be like Him, for we will see Him as He is (1John 3:2). The Bible is a book no one has mastered or exhausted. It is a marvel of continual revelation. No one knows all the mind of God (Isaiah 40:13, Romans 11:34). Even the angels do not know it all (Daniel 12:6, Zechariah 1:12, 1Peter 1:12).
Yet many people have seen some light and are either content with that, or they think they have seen everything the light has to show them, and are not pursuing greater revelation. The Lord said some people do not come to the light because their deeds are evil (John 3:19-21). They still want to hold onto some sinful pleasures they will have to give up. Others are content with their level of religious activity, and do not wish to pursue a fuller relationship with God. The greatest danger is not a lie, but partial truth. Every false teaching has some truth in it, but it is still a lie if it is not fully true according to what God has revealed in His word, the Bible. There are those that have a form of godliness but deny the power thereof (2Timothy 3:5). Then there are those who are not content to see men as trees walking, but want full clarity. God has already revealed what we need to know through the Bible. It is our responsibility to seek out the fullness of this revealed truth and apply it (Prov 18:1, Prov 25:2). We also need to seek the will of God for us individually. If we stay in the twilight zone, our eyes will adjust so we can tell ourselves that we are seeing all there is. It is far better to walk in the fullness of light (John 8-9, 1John 1-2).