Jonathan Majors and Meagan Good are becoming closer than ever as a result of his assault trial … and she’s a big reason why he’s able to push forward through a tough time.

Sources close to the couple tell TMZ … the trial hasn’t only been a tough time for Jonathan, it’s also been incredibly challenging for Meagan.

She was sitting in court for testimony from accuser Grace Jabbari and arguments from the prosecution … listening to all the negative things they had to say about Jonathan.

We’re told Meagan feels Jabbari and the prosecution are peddling BS because it all flies in the face of what she knows about JM.

Our sources say Meagan is particularly upset about the text exchanges between Jonathan and Jabbari prosecutors keep bringing up in court. In one message, Jonathan tells Jabbari, “It’s just fake,” and goes on to tell her she’s got a rep for exaggerating, lying and seeking attention.

We’re told Meagan now feels Jabbari was manipulative and controlling during her relationship with Jonathan.

By contrast, we’re told Meagan is the one keeping Jonathan grounded and centered during the trial.

Our sources say all the challenges brought on by the trial are only serving to strengthen the bond between Jonathan and Meagan, making their love even more resilient.

Another factor … we’re told Jonathan and Meagan’s deep faith in God is playing a huge role in helping them navigate the trial.

No matter the verdict, our sources say it’s hard to imagine how Jonathan would have coped with it all without Meagan’s unwavering support and understanding.