Retaliation is pretty close to vengeance. If you want to do it tastefully and respectfully read, read, read. and once you understand the ideas that others are putting forth, even if they are abusive and mean, you can refute them with soundness and with respect for what they are saying. This goes for everyone not just atheist or Christians. Every one can respect the thoughts of others. It’s better to read and understand the arguments against what you believe then to create new ones towards what others believe. Refutation over retaliation, vindication over vengeance.