I do believe in the transformative nature of the Holy Spirit, I know it has transformed me. When I was a witness and before this transformation I was susceptible to doing really stupid, selfish, angry stuff. I still had deep compassion for suffering though, and tried to alleviate it when I could. Now that I'm not a witness, I actively try to improve the world, it's awesome to have the freedom to do that. But I also feel i could not make the same mistakes I used to. I feel that the Holy Spirit keeps me from it. I know this is considered hoo-hah by most people here, but I am speaking openly.
I strongly believe there are extremely good atheist people. Give their numbers time to grow and they will be impacting the world more in very positive ways, and I think self reliance is a positive force for improving the environment etc., instead of counting on God to 'fix the mess' someday.
But I also know that I'm a better person than I was before, and I attribute this to the Holy Spirit. I believe most people are good, whether believers or not. A believer is not in essence a better person than a nonbeliever. All I can say is, I needed the Holy Spirit, I received it, and am thankful for it.