"I need to emphasize" is correct and usable in written English.
You can use it to draw attention to a certain point or to put emphasis on a certain point. For example, "I need to emphasize that it's important to stay focused on the task at hand."
I don't think I need to emphasize how terrifying that number is, particularly for the citizens of these countries, who are routinely repressed, denied basic human rights and unable to live out fundamental aspects of their identity.
(And by the way, I need to emphasize how much I dislike the term "society coverage". It implies a focus on rich white people when in fact I worked very hard to be as inclusive as possible).
If I am to help someone overcome symptoms, change behaviors, and climb out of difficult situations, I need to emphasize also all the positives he brings to the situation.
I need to emphasize that there is no evidence yet that rapamycin increases human lifespan.
I need to emphasize that hyper-function is not always an increased function.
Against this toxic view of the world, I think we need to emphasize what splendidly impure and inauthentic creatures we are.
As a pediatrician with two sons and a daughter, I acknowledge the need to emphasize manners and respect as boys maneuver into adolescence and adulthood, and to help them understand the implications and obligations of their increasing size and strength.
I submit that we need to emphasize pedagogical paradigms other than the standardized testing currently holding the attention of our policy makers, but certainly not that of our students.
I felt there was a need to emphasize this through cooperation with the humanities and theology areas".
