For three-and-a-half months, Nate McMillan convinced the Hawks to “believe.”

… Believe they could consistently win, despite a 14-20 start this season and 20-47 finish last season.

… Believe they could succeed in crunch time, despite ample fourth-quarter meltdowns in the first half of the season.

… Believe their regular-season surge could carry over into the playoffs, despite several key players having zero postseason experience, if they just stuck with what got them there in the first place.

On Wednesday night, his team pulled off the unbelievable, coming back from a 26-point deficit to stun the No. 1-seed 76ers on their home court, taking Game 5 and a 3-2 lead in the Eastern Conference semifinals. And the No. 5-seed Hawks still aren’t done.

“If you don’t believe, you better believe now,” the interim coach said after the 109-106 win as he walked into the locker room.

A team with zero All-Stars, zero All-NBA players and zero All-Defensive players, as star guard Trae Young pointed out after scoring a career playoff-high 39 points, keeps fighting, playing with a chip on its shoulder after a year of being overlooked. After setting a preseason goal of simply making the playoffs, the Hawks now have the No. 1 seed on the ropes, the chance to end the series in Game 6 on Friday at home (they’re 22-3 in their past 25 games at home and will wear their MLK City Edition jerseys, in which they’ve lost one game all season).

They continue to drastically exceed expectations. So, how far can the Hawks go?

Young isn’t putting a limit on it.

“I believe in this team,” Young said. “I believe this team can do the most. So nobody has higher expectations (for) this team than me.”

To be fair, for the first half of the season, it didn’t seem like the Hawks would head down this path. They kept crumbling late in games, with costly turnovers, defensive breakdowns and scoring droughts coming at the worst possible time. Lloyd Pierce was fired, and McMillan took over March 1. The Hawks found a rhythm and started to soar. They don’t play on national TV much, so this playoff run may be the first time many outside Atlanta are noticing.

It actually was Pierce who first declared the Hawks would make the playoffs this season, doing so March 6 of last year with the team sitting at 19-44. The season shut down five days later because of COVID-19, and the Hawks spent most of the next nine months unable to congregate as a team and have nine new players on an improved roster this season.

They mixed new talent (Bogdan Bogdanovic, Danilo Gallinari, Lou Williams, Clint Capela, although Capela was acquired last year but couldn’t play because of injury) with what they already had (Young, John Collins, Kevin Huerter).

Add McMillan as coach, and you have the formula for crushing the goals of old, even with the Hawks missing two of their best defenders long-term (De’Andre Hunter and Cam Reddish).

First, the Hawks raised eyebrows with their utter dominance of the No. 4-seed Knicks in the first round. Now, they’re one win away from the conference finals, having rebounded from two 16-point blowout losses to Philly with two epic double-digit comebacks, first by 18 points and then by 26. They became the third team in NBA postseason history to win after trailing by 22-plus points at halftime.

How did the Hawks pull it off, sustaining this over-achievement?

They’re skilled, first of all. They can catch fire quickly, as Williams’ 13-point surge in the fourth quarter of Game 5 showed, meaning they’re never really out of a game, no matter the score. They’re tough, able to wear Philly down as the game goes on, something the 76ers don’t seem fond of hearing.

But most of all, they believe.

“We’re extremely versatile, resilient,” Collins said after Game 5. “We just have a lot of depth that can come in and affect the game and change the game - as well as coach as our backbone. We can do a lot of things on this team, with the guys we have, and we’re going to continue to do so.

“... We never let it get too out-of-reach. We were competitive enough, and we believed in ourselves enough to stay in the game and go out there and get a hard-fought, hard-earned win.”

The Hawks’ belief already has gotten them much deeper into the playoffs than expected. We’ll all be waiting to see just how far it can take them.