Paul in his letter to the Romans tells us: (Rom 12:14-19) Bless those who persecute you; bless and do not curse. Rejoice with those who rejoice; mourn with those who mourn. Live in harmony with one another. Do not be proud, but be willing to associate with people of low position. Do not be conceited. Do not repay anyone evil for evil. Be careful to do what is right in the eyes of everybody. If it is possible, as far as it depends on you, live at peace with everyone.
It is possible for us to bless someone in a sarcastic manner, which is kind of what we mean when we say “Bless your heart.” But that is not the proper way for a blessing. We are called to love, genuinely love everyone, even those, maybe even especially those who make fun of us. I know that it can be hard to take and our human pride can be strained to the breaking point, but perhaps that is precisely the point. Our human pride needs to be strained to the breaking point. Our human pride, in fact, needs to be put to death.
The failure of Christianity to convert the whole world in the two thousand years that we have been working on that task is entirely due to one simple thing and that thing is human sin. Most often it is the sin of pride that ruins our presentation of the Christian life and makes our Christian witness into a masterful exercise in hypocrisy.
So what do we do or say to someone who makes fun of us? We love them, we pray for them. We live at peace with them. Or, as Abraham Lincoln said we destroy our enemy by making them our friend.