DENVER -- The family of two teenage sisters killed at New Life Church are speaking about the shooting for the first time.

David Works told ABC's "Good Morning America" that he saw gunman Matthew Murray emerge as the family was getting into their minivan after church services on Dec. 9. He said he was dressed in black and was armed with an assault rifle.

"I believe I heard a pop. I looked over my shoulder and saw a guy in black with an assault rifle. He turned and pointed it at us and then I screamed for everybody to get down,” Works said.

Works said Murray turned and pointed the gun at his family. Next Works said he remembers rushing to help his 16-year-old daughter Rachel after she was wounded before he was shot, too. His 18-year-old daughter Stephanie was also killed.

David Works and his wife Marie said their faith in God is helping them to forgive Murray, and Marie Works said she has "no reason to hate" Murray.

Father Says Faith In God Helping Him To Move On

Murray killed two other people at a missionary training school in Arvada hours before the New Life shootings.

It was a wide ranging interview, at times filled with tears and at other times laughter, as the family remembered the two girls who had devoted their lives to their Christian faith.

David Works told ABC News that some of the attack remains a blur, but he remembers the sounds.

In the chaotic moments that followed, David’s wife Marie ducked for cover and then turned to her dying daughter Stephanie. She said Stephanie died in her arms.

In one horrible attack, Laurie lost two sisters, but she said she still has her faith.

"The only thing I know is that God is love because even in that moment I could feel god there," she said.