Will everything go back into the source of light?
Yes. The context teaches that everything will be pulled back into the original source of light and energy when God destroys the present order. The elements will melt with fervent heat, and God will then create new heavens and a new earth, as Revelation and Peter indicate.
Les explains that a physicist concluded everything began from a single source of light and could return to it. Les identifies that source as God, who is light. He then says that is exactly what God will do: when everything is destroyed and the elements melt with fervent heat, God will pull everything back into the original source of light and energy, and from there create new heavens and a new earth, as Revelation and Peter tell us.