Understanding Why We Use Inversion of Control Containers for Unit Testing

I am currently looking into including Ninject in my unit tests. Looking through some very smart posts related to earlier questions ( What is Ninject and when do you use it ? , http://martinfowler.com/articles/injection.html ); I think I have some basic concepts, but I am struggling with some if its applications.

Most of the time IOCs are incorporated is because of their inclusion in your unit tests. However, as a practical matter, does it make sense to use a framework like Ninject in my unit tests if I haven't already included it in my actual codebase?

Example given below (Taken from development by James Bender with professional testing with C #: Developing Real World Applications with TDD)

[TestFixture]
public class PersonServiceTests
{
    [Test]
    public void ShouldBeAbleToCallPersonServiceAndGetPerson()
    {
        var expected = new Person {Id = 1, FirstName = "John", LastName = "Doe"};
        var kernel = new StandardKernel(new CoreModule());
        var personService = kernel.Get < PersonService > ();
        var actual = personService.GetPerson(expected.Id);
        Assert.AreEqual(expected.Id, actual.Id);
        Assert.AreEqual(expected.FirstName, actual.FirstName);
        Assert.AreEqual(expected.LastName, actual.LastName);
    }
}

      

        
        
        
      

    

As written my test using Ninject improves my life (or any bad developer who inherits my code), as opposed to just writing my test as:

[TestFixture]
public class PersonServiceTests
{
    [Test]
    public void ShouldBeAbleToCallPersonServiceAndGetPerson()
    {
        var expected = new Person {Id = 1, FirstName = "John", LastName = "Doe"};
        var personService = new PersonService();
        var actual = personService.GetPerson(expected.Id);
        Assert.AreEqual(expected.Id, actual.Id);
        Assert.AreEqual(expected.FirstName, actual.FirstName);
        Assert.AreEqual(expected.LastName, actual.LastName);
    }
}

      

        
        
        
      

    

Since I am including the principles of dependency inversion in my code; I see the importance of IOCs as a way to reduce the redundant / centralized code associated with how my classes are created (as a result of following the Dependency Inversion Principles). However, if I haven't bothered to use an IOC container in my code, is it helpful to use something like Ninject solely as part of my module framework block?