It may seem like citing your sources is tedious, but it's important and there are many reasons to do it. Attributing and documenting your sources:
Helps you avoid plagiarizing.
Allows the reader to find your research sources. Think of citations as footprints leading the reader through some of the steps you took to reach your conclusions.
Provides evidence for your arguments and adds credibility to your work by demonstrating that you have sought out and considered a variety of viewpoints on a given topic.
Is standard practice for scholars and students engaged in written academic conversations. By citing your sources, you demonstrate that you are responding to this person, agreeing with that person, adding something to what so-and-so said and so forth.