Well we are not talking about what a builder does with a chalking gun around your bathroom sink. It is a way of seeding the mind of someone to start thinking about their eternal future without direct confrontation. You can put thought provoking phrases or questions around public spaces in chalk. We use chalk (or non-toxic crayon on the footpath if you want it to be more weather proof) so that it will not damage public property and if someone takes great offence to it they can wash it off. You can also mix it up in the same area so that people are not exposed to the same sign every day.
It is not necessarily a gospel presentation but it could also be a “pre-gospel” primer. Here are some common examples for you to look at. (You should google the history of “Eternity” in connection to Sydney Australia. It is a heart warming tale.)
For example if you are going to work an area for awhile in a popular spot you could write on the footpath leading up to you (in both directions) “where are you going?” Then further up closer to you “Heaven or Hell?”. After that they could encounter you waiting to hear their answer.
You can leave them around without you even being there to soften the ground for next time. They will probably still provoke an internal response just the same.
Like everything on this site, just use your imagination, manners and common sense. In the comments below please leave some of your favourite Chalking Slogans for others to try ...
(Pictures courtesy of Jimmy BTW)