श्रीमद्वाल्मीकिरामायणे अयोध्याकाण्डे नवोत्तरशततमस्सर्गः (३४ श्लोक)
ShriRaama says this gem of a shloka while responding to Jabali maharshi:
“Like how a thief is punishable even though he illustrates great skill while doing the robbery, similarly an atheist is punishable even though he is smart. Such Veda-virodhis must be doubted by the society. The scholarly never interact with atheists”.
Hence, as far as possible, without any apprehension, we must avoid any interaction with atheists.