Friends and family took to the podium, each with their own heartfelt story.
"We come together collectively as one family tonight in memory of Sean," said Chaplain Tim Hutton.
PHOTOS: Loved ones honor NJ state trooper at vigil
"We have come to stand together in solidarity to show the family that they are not alone," said Westampton Police Sgt. Daryl Caulfied.
There among them paying tribute was Cullen's former New Jersey State Police Sgt. Paul Massey.
"Sean was a great trooper, but he was even a better person, and every single shift he made you laugh," said Massey.
Trooper Cullen's father & his sister thank everyone for coming out to support them at this difficult time. pic.twitter.com/02cczrCFgB— Dann Cuellar (@DannCuellar) March 11, 2016
"I know he's looking down on everyone of us and I just feel so fortunate that for the 20 years that I've known him," said Brian Cosby, Cullen's best friend.
The event was somber and yet filled with laughter at the happy moments they shared.
His sister said when he was 3 years old, Cullen thought he was a superhero who could fly.
"We're so happy that we know that now he's watching over us and he gained his superhero strength," said Jen Cullen, sister.
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Cullen leaves behind his fiancee, Ayrn, who is pregnant with child, and a 9-month-old baby boy, Seamus.
"He loved Seamus. He'd run through a brick wall for the kid if he had to," said Brett McCormick, Ayrn's brother. "I'm just gonna miss him."
Cullen's family, who moved to the United States from Ireland when he was 3 years old, was gratified by the outpouring of support.
"I wanna thank each and everyone of you for being here. We love each and everyone of you. Thank you is all I could say. Thank you, thank you, thank you," said Eamon Cullen, father.
Funeral services for Cullen will be held Monday, March 14.
A wake will be held Sunday afternoon and Monday morning at Saint Charles Borromeo Church in Cinnaminson.
Cullen's funeral will start at 12 p.m., and will also be held at the church.