My initial reaction would be to tell your friend to shut the Hell up. He wouldn’t appreciate your imposition of belief on him, demand the equal right to hold what is sacred and let him hold what is meaningless and pitiful. I wouldn’t word it quite so colourfully, however. But you might challenge him philosophically. Most atheists are relativists. And most atheists claim to have the intellectual high ground because they believe they are free-thinkers. However, the atheist, you might note, is just as bound to believe his credo as you are ours. Your friend, being an atheist, likely believes in the spontaneous, purposeless materialisation of the universe. Without an ultimate objective truth there can be no right or wrong, therefore his attemts to challenge your beliefs are rooted in a skewed concept of altruism. You could challenge him to the point of why he would want to ruin your sense of security in our faith when research shows that atheism is detrimental to mental health. I have a friend that was until recently an atheist. She denied the existence of God because of moral evil. She also believed in evolution, if you can dismantle biological arguments aimed your way and diffuse moral objections, than seeds of doubt, if opre-existent, can be burnt. I used to be an atheist. When I challneged my Catholic friend in high school the presence of my own morality was my stumbling block. Atheists occasionally have better morals than religious folk, and while better morals (in some cases) contribute to the theoretical ascent of man, they can just as easily be stumbling blocks. I would recommend you study Peter Kreeft. Also, there is a website I regularly peruse, admittedly it isn’t Catholic, but it is very utilitarian. The website is
www.godandscience.org which is run by a convert from deism named Rich Deem. There are an extensive number of articles dealing with the scientific (astrophysical, biological, philosophical and sociological) fallacies of atheism. But in the end, you can only pray for your friend. If the heart is too hard than it won’t pump sufficient levels of oxygen to the brain in order for proper thought to occur. In the end, if your friend can’t respect your beliefs, which conttribute to who you are, than he really isn’t your friend. I pray for your success.
God bless,