Knowing the bias of a news source helps us to keep perspective on featured stories and how those stories are presented. It helps us find the truth and develop a balanced understanding of an event or issue
However, we are human, and as such, we are more likely to believe the news that fits with our view of the world. This is called confirmation bias. Add to that the relentless nature of the news cycle, not all of the "news" being verified and factchecked. Gary Marcus and Annie Duke, reporting for the Wall Street Journal (9/01/2019) note: "The simple act of repeating a lie can make it seem like truth, as the Temple University psychologist Lynn Hasher and colleagues showed in a pioneering study published in 1977 . . . Test subjects became more likely to believe things as they were repeated, regardless of whether they were true or false. They third time they heard a statement, they were just as likely to believe is as a true statement that they had heard once."
If you are concerned, know that we can be fully informed when we read and listen while recognizing our own bias and that of our news sources.
Check the chart below for bias ratings of many common news sources: