Isn't it repugnant to take advantage of a person's weakness to gain converts?

I notice bible fundamentalists prey on people who are at their lowest point in their life whether financially, physically or emotionally. Bible fundamentalists bombard them with fake attention, fake love and fake friendliness with the ultimate agenda of converting them to their (bible fundamentalists) club at the same time feeding them with biases and hatred for others. People who are at their lowest point in life are easy prey and bible fundamentalists know it and take advantage of the opportunity to get them to their side.