As Christians, we need to focus on the future and maximize our time here on earth. I have found myself sometimes horrifically eaten up over someone not responding spiritually, spending all of my energy and emotion on them, preventing me from even considering helping others. Consider this from Luke 9:

"Another also said, “I will follow You, Lord; but first permit me to say good-bye to those at home.” But Jesus said to him, “No one, after putting his hand to the plow and looking back, is fit for the kingdom of God.” (v61-62)

We can't let someone who doesn't respond be the absolute focus of our attention. If you find a bus wreck and are helping people out, you can't let the one person who refuses to leave the fiery wreck be your sole objective. Sure, if you pass by them, ask them if you can assist, but don't ignore the people who will respond in favor of the one who won't! Maximize your ability to take care of the lost!