In SharePoint 2013, how to embed one site page into another?

Question

I have some common content as Site Pages, lets call it "Page 1", which I want to show in "Page 2" and "Page 3", just as it is shown in Page 1, so that I can just update Page 1, and Page 2 and Page 3 will start showing the updated content. All pages have simple HTML Content.

 

I can see it has to do something with Web Parts. But for the love of my life, i am not able to achieve this.

 

Please note that I am using enterprise SharePoint 2013, so if there is a setting that can block me for achieving the above, please let me know, so that I can get it corrected.