“He was a moderating influence,” Mr. Moore said. “He wanted this system to work. He believed in it. I guess from the vantage point of a congressman that makes sense. But he was mindful that from our vantage point in a city like Baltimore, you have to keep wondering how is this going to work.”

One example was Mr. Cummings’s response to President Trump’s attack on Twitter this summer in which the president called his district a “rodent infested mess.”

Mr. Cummings replied calmly: “Mr. President, I go home to my district daily. Each morning, I wake up, and I go and fight for my neighbors.”

“He was being nice to him,” Mr. Moore said, “and I didn’t agree with him being nice to him.”

But that spirit is what made Mr. Cummings unique, his friends in Baltimore said on Thursday.

He was “so much larger than who he was,” said Bishop Walter Thomas, the pastor of New Psalmist Baptist Church , a sprawling, cream-colored building in West Baltimore, where Mr. Cummings was a member and had attended services most Sundays for decades. “He was something so different,” Mr. Thomas said. “He was not the angry protester. He was not the passive peacemaker. He was the deliberate man who stood for right and wrestled wrong until right became the natural winner.”

Even after Mr. Cummings faced health challenges, he never lost his drive as a community activist, Mr. Thomas said.

Mr. Thomas remembered walking arm in arm with Mr. Cummings, trying to calm the crowds, during the riots after the funeral of Freddie Gray, who had died in police custody in 2015.