I'm not sure if I would use a quote from an atheist to make the point you're trying to make.

If Penn Jillette is an atheist, why does he care whether or not Christians share their faith with other people?

He would meet fans after the Penn and Teller shows to sign autographs, stand for pictures, etc. After one show, he noticed a gentleman hanging back from the other fans, allowing them to interact freely with Mr Jillette. When all of the others were leaving, the gentleman approached Penn and said, "Sir? I recently heard you say that you were an atheist and I want to give you a gift." Penn was not expecting this but accepted the box from the gentleman's outstretched hand. He opened it to find a Bible in the box, which really surprised him. The gentleman explained that he was very concerned for Penn's eternal life and wanted to make certain that he a chance to read God's word before he met his maker. He also told him that he was free to read it or not as he saw fit, but if he read any portion of the Bible that he, the gentleman, had written within the front cover all his contact information. If Mr Jillette had any questions, day or night, to feel free to contact him.
Penn got back to his room still taken aback by the encounter. It continued to bother him as he tried to sleep that night. He finally got out of bed and made and posted a video detailing the encounter, minus the gentleman's contact details. His takeaway from it was that with the many people claiming to be followers of Christ that he had never been approached him by someone this caring and sincerely concerned for his future well being. He was shocked that more people weren't approaching him and every other atheist this way. The quote I used is an excerpt from that video. I'm guessing the full video can be found on YT.

Thank you for telling the full story. But I don't see Penn Jillette accepting Jesus Christ as his Lord and Savior for the following reasons:

1. He went to Sunday School as a kid, but got kicked out for turning his fellow students into atheists.

2. He owns two cars. One car has a license plate reading "Godless", the other has a license plate reading "Atheist".

I suspect that he will not accept Jesus as his Lord and Savior. We may never know one way or the other, but we don't have the ability to change his or any other's heart and mind. Only God has the ability to do that. We are commanded to share the good news; to explain our faith and trust of the one true God with gentleness and respect. Some of us plant seeds. Some of us shine the light of truth. Still others water growing faith or stand between the Predator, the enemy of God, and those he would rip up from the fertile ground. Qureshi Nabeel spent much of his youth as a Muslim evangelist, doing his best to destroy the fledgling faith of his young classmates til he encountered a young college classmate who was ready to give a reason. He turned to Jesus and spent the rest of his life passionately ready to give a reason. I imagine Saul was voted most likely to never be a worshipper of The Way... until he was Paul. I always carried my faith and my scriptures to work but after hearing of Mr Jillette's encounter, I kept extra Bibles at work. I gave them all away in very similar circumstances before retiring. We aren't all Billy Grahams or Charlie Kirks but we were all uniquely created to be Jesus' hands and feet. The weaker we are the more His Glory shines through.