In 313, and especially if you are in the Roman West, your beliefs are still the majority view. And Roman civic institutions and religious cultures will hold sway, especially among the upper classes, for at least another 80 years, though they will begin to be more ambiguous in the West toward what would be the end of your life, especially after the Altar of Victory controversy sparks questions in 357CE, and Ambrose makes the case for de-embedding pagan religious traditions from Roman politics. But that is going to be FAR from a decided issue at any point in your life.

Instead, your experience pursuing political advancement would be competitive and fraught with sectarian disputes as competing bases of power in Roman civic institutions jockeyed for influence. This would make it difficult for everyone, but your pagan background would not be a permanent bar to social mobility. We only have to remind ourselves that, in the Eastern Empire, the rhetor and philosopher Themistius flourished with friends in the pagan and Christian worlds throughout the 4th century CE.

On the Altar of Victory, Symmachus and the context of this question in the Roman West, check out Christiana Sogno's extraordinary study of Symmachus (https://books.google.com/books/about/Q_Aurelius_Symmachus.html?id=N3qFtZRLuXgC). And for Themistius, check out Vanderpool and Swain's work that is still pretty recent (https://books.google.com/books?id=hPIHapo0o1IC&printsec=frontcover&dq=Themistius&hl=en&sa=X&ved=0ahUKEwi2iOaU-LLPAhWEbT4KHcVfDrYQ6AEIHjAA#v=onepage&q=Themistius&f=false ––and–– https://books.google.com/books?id=AeRBCgAAQBAJ&pg=PA53&dq=Themistius&hl=en&sa=X&ved=0ahUKEwi2iOaU-LLPAhWEbT4KHcVfDrYQ6AEIMjAD#v=onepage&q=Themistius&f=false)