Fourth Article of Faith
Following close on that thought came another: if this is an appropriate unit of principles and ordinances (i.e., these four things are the "first" group), is there a second unit? A third?
Of course, almost immediately I realized that the "second" unit of principles and ordinances would be those taught and practiced in the holy temple. There, we learn more of God's plan for us and of the grand possibilities that lay before us, as well as being able to participate in further covenants that more closely bind us to His path.
Then, I asked myself, what - if any - would the next "unit" of principles and ordinances be?
Well, we believe in eternal progression... so are the temple principles and ordinances the last that we will ever participate in? The answer seems like it must be no. There must be more. After this mortal life, those who HAVE done what they should, have followed the Lord's path and taken advantage of the blessings of the Atonement (critical), will be permitted to take advantage of further ordinances and learn greater principles in the Celestial Kingdom.
This is, of course, not doctrine of the church of Jesus Christ of Latter-day Saints. Just my own thoughts on the subject. But I rather like it: we begin with faith and baptism, we progress to the actual learning portion of our progression at the temple, and then we finally practice what we have learned in the hereafter, when (if we are faithful) we are made joint heirs with Christ and given all that He has: learning ever-greater principles, participating in ever-holier ordinances, and finally coming to the finality of Grace and the Perfection that Jesus has commanded us to attain.