He said: "Having children changes how you look at life, what matters, what's a priority. And then you have a few uphill battles - well, that makes you even more resilient."
The 36-year-old singer is a hands-on dad and loves spending as much time as possible with his two boys. He told USA Today newspaper: "I'm with my children all the time in Atlanta. When I'm on tour, they come in and out. Usher's more active; I can be out in the park with him for two hours, just throwing a ball around. Naviyd loves to read, loves to see shows. I love to have him with me in New York."