The shooting at a music festival in Las Vegas left 58 dead and 515 injured.
Following the tragedy, Trump said: "Scripture teaches us 'The Lord is close to the broken hearted and saves those who are crushed in spirit' - we seek comfort in those words for we know that God lives in the hearts of those who grieve."
When asked previously what his favourite Bible verse was, Trump was not able to provide one.
In Monday's speech, which continued much religious language, he also said: "We call upon the bonds that unite us, our faith, our family and our shared values.
"We call upon the bonds of citizenship, the ties of community and the comfort of our common humanity...At times like these I know we are searching for some kind of meaning in the chaos, some kind of light in the darkness. The answers do not come easy.
"Melania and I are praying for every American whose been wounded or hurt...we pray for the entire nation to find unity and peace and we pray for the day that evil is banished and the innocent are safe from hatred and from fear. May God bless the souls of the lives that are lost.
"May God give us the grace to heal and may God provide the grieving families the strength to carry on."