DC Comics' Trinity is one of the greatest superteams ever formed, as Batman, Superman, and Wonder Woman represent the greatest their universe has to offer. The trio has starred in many adventures together and come out victorious against the biggest threats in the cosmos. But, the Dark Knight once admitted a different DC hero belonged on the team instead of him, as revealed when he told Black Lighting he's "always known" he deserves the spot on the Trinity.
In DC's main universe, the Trinity has almost always referred to Batman, Wonder Woman, and Superman. The Justice League offshoot brought together the three pillars of DC Comics on a team that just focused on the publisher's most popular characters. While the trio of heroes has worked alongside each other for decades, the Trinity title and comics didn't arrive until the early to mid-2000s. Batman, Wonder Woman, and Superman are all worthy of spots on DC's Trinity, but in an issue of Batman and The Outsiders, the Caped Crusader admitted Jefferson Pierce's Black Lightning should be on the team instead of him.
In Batman & The Outsiders #16 by Bryan Hill, Dexter Soy, Veronica Gandini, and Clayton Cowles, Black Lightning successfully defeats Ra's Al Ghul by hitting him with a powerful blast of energy. Batman arrives on the scene to tell the leader of the Outsiders Ra's won't soon forget him. Jefferson responds by telling the Dark Knight he feels like he has more power than he ever thought he did. Batman admits to Black Lightning he should be standing alongside Diana Prince and Clark Kent and he's "always known that."
Batman's admission is correct. Black Lightning is one of the most powerful people in the universe, whose full powers are still untapped. Next to two god-like figures in Wonder Woman and Superman, he fits right in. At the same time, Bruce Wayne realizes he doesn't have anywhere close to the kind of powers Black Lightning possesses, nor is he quite the hero the leader of the Outsiders is.
It's definitely true Batman might have undervalued his own contributions as one of the greatest heroes the DC Universe has ever known - as his spot on the Trinity is deserved. However, he's not afraid to admit Black Lightning is a hero whose powers and public perception are much better aligned for the Trinity. He completely respects Jefferson Pierce for the hero he is, and knows he's near, or on the same level, as both Superman and Wonder Woman. However, there's no reason Batman couldn't keep his spot on the team and welcome Black Lightning as a member of the new Quadrinity. The hero has earned his place on the team.