We all have the power to make a difference. The first step is to pray as if everything depends on God because it does, but work as if everything depends on you.
“Work” in this case does not mean some great action. Little actions with great love are far more powerful.
Smile at people walking down the street. Speak to the ones at work, in school, or on the bus that nobody else is talking to. Stand up for people everywhere who are getting bullied. You do not have to say "What are we going to do about this?" and look to others for the answer.
These are all simple actions that can have an extraordinary impact in the world around us. When coupled with prayer, they only grow in their sincerity.
Through prayer we are drawn closer to God. We are then allowed to see Him more clearly in our fellow man. When this recognition of divinity in others enters our hearts, we are endeared to treat our fellow man with respect. That respect fosters genuine care for others.
Who knows when today's shooter decided to kill others. Who knows how his heart descended into evil. It is nobody's fault except the shooter that he opted for violence instead of peace. But simply because the blame lies with the shooter, that does not mean we are all abdicated our duty to prevent future hate. We all have a responsibility to care for one another's wellbeing.
To be clear, there are great debates and governmental reforms that need to happen to prevent shootings like the one that America saw today. What changes in our laws that are needed to keep our social contract intact while maintaining our freedom and security remain to be seen. The American people are either going to have to make those choices in the ballot box or elect worthy politicians to make these reforms. But, if politics is downstream culture, America should start by creating a culture dedicated towards loving one another.
Indeed, America's best days are ahead of us if we choose to stop looking in the past at what would have, could have, should have been if only somebody made a difference in this evil person's life years ago. What if instead we chose to love one another in the same way God loves us? In effect we can become an extension of Him. When that happens, He shows through our actions. Your kindness could be the shining grace and face of God needed to convert hate in a lost soul's heart.