The shooting happened at Friendship Baptist Church in the 200-block of South Laramie Avenue right before service at about 11 a.m.
Emmanuel Fleming, 34, a church usher, and Michael Swift, 46, were killed. Police believe Fleming may have been the intended target. The men were killed in front Fleming's three children who had to run for cover.
Parishioners inside the church heard the gunfire and took cover.
Police are looking for three men suspected in the shooting. They were wearing bandanas over their face, but may have been captured on police cameras. Police believe they may still be in the neighborhood and are looking for a silver or gray SUV that the men drove away in.
On Monday, community leaders echoed the same thought: If a shooting can happen on the steps of a church in broad daylight, the violence has gotten out of control.
"There should be a sanctuary from violence, and I believe that the church should be one of those sanctuaries, and yesterday we had the unfortunate incident happen here, two young men on their way worship, one with three young sons between 6 and 10 years old, who had to witness their father being gunned down and it's time for us to make a change in our city," said Rev. Reginald Bachus of Friendship Church.
"When this cycle of violence reaches the doorsteps of a church, we are really in trouble," said Chicago Police Cmdr. Dwayne Betts.
Sun-Times Media Wire contributed to this report.