which server-side programming language should I use for my large scale web application?

Admittedly, I was inspired by an already existing thread. However, it was asked 7 years ago, implying web programming has evolved drastically in the meantime. Plus it is closed for further discussion, preventing me from asking further questions. I spent hours upon hours (and will continue doing so) examining the various server-side programming languages and many people convey conflicting opinions.

So far, Python, Java, PHP, C#/.NET/ASP.NET and possibly Google Go are in consideration, but I'm open to others. Namely, I'm an intermediate programmer who has done both web development with PHP and object-oriented programming with C++. However, it is important to mention that I'm not very knowledgeable about anything related to servers, but I'm extremely willing to learn.

Namely, my project will need these characteristics: fast, secure, scalable. The server will most likely be run on Linux for better performance. Why I need these characteristics is due to the fact that it will be a large-scale web service that might have millions of sensitive and small data packets per second that are constantly communicating between the client and the database.

Any advice, direction, materials or input is appreciated!