Albeit lighter on Christian theology than some devotionals, Daily Wisdom strives to offer insightful advice for all people, whether they follow Christ or not. They publish a devotional the majority of days that you can have sent to your inbox or RSS reader.
The following excerpt from their author’s page does a perfect job of explaining their mission and direction:
DW is not a conventional “devotional” but a daily message with an evangelistic or apologetic emphasis. Since DW is meant to appeal to a not-necessarily-Christian audience, we avoid phrases like “we, as Christians…” and words like “sanctification” that only believers understand. We steer away from “Christianese” – cliches only Christians use – and references to Bible verses, etc. understood exclusively by Christians. That’s not to say we don’t quote Scripture, only that when we do, we quote the verse itself, avoiding phrases like, “In Matthew where Jesus talks about the narrow gate…” We prefer “Revelation chapter 3, verse 6 says…” to “In Revelation 3:6, God says…” Submissions must not assume the reader is familiar with Bible stories or books of the Bible.
The site also publishes a quotation every day called 1liner. While not always written by theologians, they often have theological implications.