Ways to Encode context for text classification?
A Recursive Neural Network (RNN) is best suited to solve your problem. And if you want to take a step further try Recursive Neural Tensor Network. You can generate compositions for entire sentences using RNN both for your content and context data. This will help you map your sentences to a higher dimensional space and as an output you will get numerical values (or embeddings) both for your content and context. Feeding these values into a simple logistic classifier will do your task. For a brief overview on RNNs take a look at this lecture by Richard Socher.