Of course you can—it happens all the time. But that doesn't make it okay. Most people know that you should not use exact words or sentences written by someone else without providing a citation for the quote. But you should also avoid using other people's ideas. If you have paraphrased someone else's work, you must cite your source, even if you use your own words. However, if you interpret someone else's ideas, using mostly different words and putting your own spin on the topic, then you will be okay.
One more thing: if you read the same idea in three or four different sources, and they don't seem to refer back to one original source, then you can consider that idea to be common knowledge. Even if it's a new idea to you, it is probably common knowledge to the practitioners in that field of study. You can safely use common knowledge ideas without citation.
But keep this in mind: according to research expert William Badke, "...the point of a research essay is not simply to quote or interpret others, but to evaluate their work and provide your own arguments" (243).
Badke, William. Research Strategies: Finding Your Way Through the Information Fog. 4th ed. Bloomington, IN: iUniverse, 2011. Print.
Why is avoiding plagiarism so important?
What is plagiarism? The dictionary's definition is: "Using ideas, plots, text and other intellectual property developed by someone else while claiming it is your original work." Plagiarism is theft; plagiarism is a lie; plagiarism involves pretense and deception; plagiarism is a violation of the DBU Honor Code.
Why does DBU have an Honor Code? Consider Colossians 3:23:
"Whatever you do, do your work heartily, as for the Lord rather than for men."(NASB)
Here is the same passage, plus the surrounding verses, as it appears in the The Message paraphrase edition:
"Servants, do what you're told by your earthly masters. And don't just do the minimum that will get you by. Do your best. Work from the heart for your real Master, for God, confident that you'll get paid in full when you come into your inheritance. Keep in mind always that the ultimate Master you're serving is Christ. The sullen servant who does shoddy work will be held responsible. Being a follower of Jesus doesn't cover up bad work."
Your opportunity for an education at DBU is a gift from God. Don’t allow dishonesty or laziness to tarnish that gift.