"My goodness, what would this world be like two years in had we not been fact-checking the president and exhausting ourselves, chasing these so-called bright shiny objects, had we not been fact-checking him, what would be our concept of reality today? What would be our concept of the truth?" he asked.
He made those comments to C-SPAN's Book TV during an interview set to air on Saturday and Sunday.
Acosta's appearance came as he promoted his new book -- titled "Enemy of the People" -- in which he details his time reporting on Trump's White House.
The controversial reporter has caught headlines for his testy confrontations with the president and his press secretary. At the end of 2018, the White House suspended his press credentials only to have them restored after CNN took the issue to court.
Trump has responded to CNN and others by blasting "Fake News" about his administration. But according to Acosta, he and other reporters are more honest than the president.
"We have been far more honest and straightforward with the American people than President Trump has," he said during another interview. "Are there times when we fall short? Sure. But the press issues corrections. When was the last time you saw the president issue a correction or a clarification? It’s a rare thing for Donald J. Trump."
His book also pushed back on the idea that the media should follow "neutrality for the sake of neutrality." “Neutrality for the sake of neutrality doesn’t really serve us in the age of Trump,” he reportedly said.