def login_user(request):
state = "Please log in below..."
username = password = ''
if request.POST:
    username = request.POST.get('username')
    password = request.POST.get('password')

    user = authenticate(username=username, password=password)
    if user is not None:
        if user.is_active:
            login(request, user)
            state = "You're successfully logged in!"
        else:
            state = "Your account is not active, please contact the site admin."
    else:
        state = "Your username and/or password were incorrect."
    request.session['user'] = user
    return render(request,'auth.html',{'state':state, 'username': username, 'info':'info'})

@csrf_protect
def home(request):
    if "user" in request.session:
        user = request.session['user']
    else:
        user = None
    return render_to_response('home.html', {'user_name' : user}, context_instance = RequestContext(request))

def login_user(request):
    state = "Please log in below..."
    username = password = ''
    if request.POST:
        username = request.POST.get('username')
        password = request.POST.get('password')
    else:
        return redirect('login/')

    user = authenticate(username=username, password=password)
    if user is not None:
        if user.is_active:
            login(request, user)
            state = "You're successfully logged in!"
        else:
            state = "Your account is not active, please contact the site admin."
    else:
        state = "Your username and/or password were incorrect."
    return render(request,'auth.html',{'state':state, 'info':'info'})

from django.contrib.auth.decorators import login_required
from django.shortcuts import render

@csrf_protect
@login_required
def home(request):
    return render(request, 'home.html')

{% if user.is_authenticated %}
    <p>Welcome, {{ user.username }}. Thanks for logging in.</p>
{% else %}
    <p>Welcome, new user. Please log in.</p>
{% endif %}