Laravel Authentification doesn't work

I'm working with laravel 5.2, and I have a problem with customized authentification. It doesn't log the user on .
Here you can find my code for the function :

public function login(Request $request)
{
    $this->validateLogin($request);

    $email = $request->get('email');
    $user = User::where('email', $email)->first();

    if(! is_null($user))
    {
        if (Auth::login($user))
        {
            return redirect('/profile');
        }
    }
    else
    {
        $this->register($request);
    }
}

In the place of Auth::login, I tried also the function attempt and check, but nothing was working ...
It logs the user, but it showed a blank page, without redirecting to the url..
Can you help me plz?
Thanks alot

via Chebli Mohamed