Is it true that not inviting non-Muslims whom I have come to know will lead to them disputing with me on the Day of Resurrection, and does this apply to everyone I meet, or is it limited to those whom I know well, including colleagues, neighbors, and those I know on the street?

Calling to Allah is generally a collective obligation (fard kifaya), and it becomes an individual obligation (fard ayn) in specific situations, such as when there is no one else to do it, or when there is a gap that only that individual can fill. Disbelievers who have not received the call to Islam will not be opponents of Muslims on the Day of Judgment; rather, they will be tested. As for those who have received the call and rejected it, the proof has been established against them, and a Muslim does not bear sin for not calling them again. It is an individual obligation (fard ayn) to call those whom the message has not reached, or those who seek to learn about Islam. The diversity of modern means of communication makes da'wah easier and increases the obligation on rulers and the wealthy to spread it.