How should a Christian respond to someone saying, "there is no God"

"So then, my beloved brethren, let every man be swift to hear, slow to speak, slow to wrath; for the wrath of man does not produce the righteousness of God" James 1:19-20
This verse is good of what not to do. But what should you do?
Jesus wasn't threatened nor offended by non believers and scoffers, quite the opposite, in fact. We are told over and over again in the Gospels that Jesus wept over Jerusalem because of unbelief. Jesus spoke about hell more than He did about heaven, actually. Nevertheless, He never campaigned to silence the non believer and their agenda, but continued to tell all who would listen that He is the Way, the Truth, and the Life. He never robbed anyone of their freedom.
The Bible teaches that we are to expose false teachers and stand firm on and in the word of God, but it also says we are to do it with grace, love, and respect for all people.
Jesus told us this world is not our home; He told us that people are blind and dead in their sin without Him. I think we are guilty of forgetting that we were once blind and it is only by the grace of God that we were able to respond to the truth. It must be the reason we get up tight and self righteous when things that challenge God come up. We think we are doing God a great service by standing up for him, when really; we are pushing people further away.
The Bible tells us that the ruler of this world is Satan and he blinds the eyes of non believers. We say we believe in eternal separation from God and hell. If we truly believe this, shouldn't our response be to weep as Jesus did? Shouldn't our first thought be a prayer that God would lift the blinders from their eyes as He did ours? Unfortunately, this isn't always the case, instead we are angered and appalled. This is not the heart of God.
An Atheist stands firm in faith that there is no God. They are fully convinced they can live as they please and they will not be held accountable. Think about it for a moment. No matter what comes their way, giving cause to doubt, they shake off and remain firm in their faith. How many Christians turn from God the minute they don't get their way?
How should a Christian respond to "There is no God"? I believe it should be with weeping and prayer.
"...Or do you despise the riches of His goodness, forbearance, and long suffering, not knowing that the goodness of God leads you to repentance?" Romans 2:4

If someone said "there is no God" to me, I would quote scripture, and then I would pray for the person that said it. Or, maybe I would just be silent and pray for them.

God bless.