Passport is an excellent choice (I'm the developer). It is the most flexible and easily integrated authentication solution for Node.js. It also has the most comprehensive test coverage, essential for such an important component of an application.
Adding to this solution and some of the comments, Passport is great, it solves the Authentication piece. StormPath is another api that will work with Passport and provide User Management and Authorization.
here is the link to its rest api, which can be used to integrate with your application.
Note: StormPath is a hosted service. They have a free-tier, which can suit small to medium applications.