On Tuesday evening at London's Olympic Stadium, the South African won with a time of 43.98 seconds. This is the third gold medal he has received in major championships over the past three years.
"It's such an honour for me to finally say that I've got three golds in three years, it sounds good, and it feels good," he said. "It's a massive honour, and I thank the Lord each and every day for this great blessing and this great opportunity that I have."
"I just thank the Lord for continuously helping me go through each and every competition healthy and strong, and for every race as well I pray that all my competitors are healthy and come over the line healthy, and I think our prayers were answered today."
Van Niekerk has frequently talked about his Christian faith.
Last year after winning gold at the Rio Olympics he told Premier's media partner, Passion for Sport: "Everything that comes my way I thank the Lord.
"I leave every race, every step that I take in his hands.
"I trust him in everything I do.
"He's the one that blessed me with this talent."
His gold in Rio was also accompanied by a new world record which beat the previous record US sprinter Michael Johnson held for nearly 17 years.