While some evangelicals may not know it, a large number of believers regularly sing a doxology called the Gloria Patri:
(Traditional musical setting by Cynthia Clawson)
The problem comes from the second to the last line.
World without end certainly sounds like it is describing maybe being in heaven, or maybe, just a very long period of time on the earth (as Ken Follett uses it in his novel with the same title). Follett uses "World Without End" to describe the stable world of late Medieval Europe. But, like many people, he is totally misunderstanding the phrase. The is not surprising, since the traditional "world without end" translation of et in saecula saeculorum is confusing at best, and misleading at worst.
Trying to figure out the meaning by looking at the rest of the lyrics doesn't help much. Translated literally, what the original Latin actually says would be closer to "in world of worlds." The word secular, in fact, is based on the Latin saecula. But, even the more literal translation still leaves many unclear about what the phrase means.
One important key is to think more broadly about how we use the word "world." Someone might say, "In the world of Julius Caesar, the Roman Republic was widely corrupt." Used that way, the word "world" is not about a place as much as it is about a time. You could say, "In the age of Julius Caesar, the Roman Republic …"
That same alternate sense is also true of the Latin word saecula. Saecula saeculorum can be translated as, "age of ages." Some might already see where this is going, because they remember some of the ways that phrase is used in the New Testament. In fact, if you sang the Gloria Patri in a Greek orthodox church, you would end the song by singing, "Kαὶ εἰς τοὺς αἰῶνας τῶν αἰώνων." This is exactly the same phrase found in Greek text of Galatians 1:5; Philippians 4:20; Revelation 1:18, 4:9, 5:13, 7:12 and in many other passages. If you look and don't see "ages of ages," that's because it is usually translated "forever and ever."
So, the song is actually a praise of the Triune nature of God.
(Musical setting by Karl Digerness)
The same theme is found in other songs. "Age to age He stands. And time is in His hands. Beginning and the end. The Godhead, Three in One. Father, Spirit, Son. The Lion and the Lamb." – Chris Tomlin in "How Great is Our God"