Is there an application instance after running any component?

Do I have to be sure that if any of my application component is running (onCreate for Activity / Service, onReceived for BroadcastReceiver, etc.), then my application instance of the Application class already exists?

I have a static instance field in my application class

  public class MyApplication extends Application {
private static MyApplication instance;

@Override
public void onCreate() {
    instance = this;
    super.onCreate();
}

    public MyApplication getInstance(){
         return instance;
    }

Of course, this class is registered in the manifest. I wonder if using a static instance field is safe and always returns me the correct value. I have not used content providers before, but will it work with content providers?