The only assumption I have to make is that hard solipsism is not true.
This assumption does not change for strong or weak atheism, nor theism.
This assumption does not change for strong or weak atheism, nor theism.
You'd believe if you just opened your heart" is a terrible argument for religion. It's basically saying, "If you bias yourself enough, you can convince yourself that this is true." If religion were true, people wouldn't need faith to believe it -- it would be supported by good evidence.