Inactive Christian is an oxymoron. Christ was never inactive, and so neither should an authentic follower of Him be.
As Kierkegaard wrote,
The highest of all is not to understand the highest but to act upon it.
I think your statement is an unfair judgement on Christians. Christians in that tragic moment were likely helping others just as reports have told all people were. Christians all over the country, and the world, can only actively pray that God works in the aftermath of that evil act, and can show the many people involved that
The sufferings of this present time are not worth comparing with the glory that is to be revealed to us … For the creation was subjected to futility, not willingly, but because of him who subjected it, in hope that the creation itself will be set free from its bondage to corruption and obtain the freedom of the glory of the children of God.
My friend, the Christian God is an active God. Prayer itself is an action, so if a Christian is actually praying, then that person cannot be an inactive Christian.
The problem is not the Christian, but people who seem to think Christianity is some system of morality, and simply see every Christian who fails to live up to that morality as hypocritical. But in reality, Christians are just as messed up as everyone else, and Christians mess up just as much.
Where sin increased, grace abounded all the more,
But the Christian is set free from that sin through grace, and this freedom gives that Christian the opportunity to transcend his or her own iniquities and be in complete service to others. We are both saint and sinner, my friend. It is a tightrope.
This is a rather broad refutation of your short comment, but I hope you may think over these things, and I hope that if you choose to respond, it is with thoughtfulness and a willingness to engage in the pursuit of Truth.