Neurochemistry cannot explain every facet of love. It doesn't explain why these chemicals are released when we meet some people but not others. This would suggest that there is more to love than chemistry. It must depend on a set of preconditions, which could be emotional or spiritual.
These chemicals in the brain do not only produce the feeling of love. For example, dopamine does not only produce euphoria, it also heightens concentration (which is why it is in ADHD medication). People who take drugs like Adderall, which trigger a dopamine release, do not immediately fall in love with those around them. Therefore, love cannot be simply reduced to the production and presence of dopamine and norepinephrine.