Hegel said Marx objectified the predicate. This is inevitable and is not a cause for dismay. The problems with which you will be concerned have been examined by other thinkers, often over long periods of time. It is only sensible in approaching these problems that you should look at these earlier discussions. There is, however, an important distinction to be drawn between this general reliance on the ideas of others, and plagiarism.
Plagiarism can take at least two forms.
First, it may consist in copying out verbatim lines from someone else's work without any acknowledgement that the words you are using are not your own. Secondly, it also includes cases in which there is a substantial overlap in vocabulary and sentence structure between what you write and what is said by the text you are using. Your grasp of the views you want to write about should be good enough for you to be able to formulate them entirely in your own words. You should also give full details of the source of the quotation, i.e. details sufficient to enable readers to look up the quotation for themselves. This will mean giving at least the page number, the exact title, and the author of the book from which you are quoting.