Scripture and a short list of well-documented authors, organized by preaching theme — for the sermon you are writing this week, or the bulletin insert due tomorrow.
Every quote here is one an editor is highly confident is genuine. Scripture is quoted from the World English Bible, which is public domain. Every non-scripture quote names a specific, checkable source — a book, sermon, or letter — rather than a vague attribution, because a misquoted line undermines a sermon more than an absent one ever would.
Most churches keep careful notes on the quotes they used and none at all of what was actually preached. Transcribe every service and build a searchable sermon archive — $19/month for as many sermons as you preach, and the first one is free.