NowaThese days, some think that violent video games teach people that aggressiveness is normal in everyday life. These days, some think that violent video games teach people that aggressiveness is normal in everyday life.

But I personally don't think these have seriously harmful effects on the community or character of humans, and I will support my opinion with an example below I personally don't think these have seriously harmful effects on the community or character of humans, and I will support my opinion with an example below

Removed the 'but' because the rest of your sentence makes it clear that you'll disagree.