Let X \sim \mathcal{N}. “How much more likely is x=10 than x=5?” We note that P(x=value) = 0 for any value if X is continuous. However, we can still get an answer:
\begin{equation} \frac{\dd{X} P(x=10)}{\dd{X} P(x=5)} \end{equation}
these two things cancel out. Therefore, you can just divide the PDF:
\begin{equation} \frac{f(x=10)}{f(x=5)} \end{equation}