I’m fine with people who are “more observant or less observant.” People who understand that they are not keeping the Torah yet and know that. They might drive a car on Shabbos knowing that its wrong, but they view themselves as not yet observant.
Then there are jews who are apikorsim. They think that the Torah nowadays allows driving a car on Shabbos. While it would still be great to be mekarev them, one must understand that they are arguing with someones religious beliefs. Those are harder to change. I personally would allow my child to play with a not yet observant neighbor but not with an apikorus.