Or from the Calvinists, why bother because you can't change a thing.
GREAT question!
Yes it was. Sadly, you missed the point.
Here's the thing. Both Wesley-Arminians and Calvinists preach the gospel because we are commanded to do so. It's all about obedience to the Word. But only the Wesleyan-Arminians believe it will make a difference.
If the Wesleyan-Arminians don't share the gospel, people might be lost. If the Calvinist doesn't share the gospel, only the Calvinist will be judged for the disobedience.
But then if you're one of the "special" ones, that doesn't matter either.
I think this is a fair statement in general. On both sides are people who use their theology as an excuse not to witness, and in both cases this is disobedience to the Great Commission.
Huh?
Of course Calvinists believe that the preaching of the Gospel "will make a difference". We know that the result of the Gospel being preached is the conversion of some sinners and the hardening of others. We know that the preaching of the Gospel is the sowing of the seed that God uses to grow His church.
The one difference between Calvinists and non-Calvinists is this: Calvinists know that God saves as a result of the preaching of the Gospel. Non-Calvinists hope that people will make the decision to accept salvation as a result of the preaching of the Gospel. (As has been pointed out, this leads to differing methods of preaching the Gospel.)