One of the other major subjects that came up over Shavuot was the ideal nature of service to God.
A standard Jewish tenet asserts that someone commanded to perform a service receives a higher reward than someone who voluntarily performs the same service. For example, men are commanded to eat in a sukkah on the holiday of Sukkot, while women are not. A man receives a "higher reward" (whatever that means) for doing so than a woman does.
A very cursory look at this tenet might leave you confused: after all, one is doing it because he has to, while the other doesn't have to but does it anyway. Surely the latter should get a higher reward.
Looking a little deeper, however, reveals that the tenet makes some sense. It is human nature to resist things that you are commanded to do. Not only has the joy been taken out of it, but your will has been taken out of it. Whereas, a person who is moved to do what they want to do anyway, when they want to do it, and with the ability to not do it when they want - sure, it's a nice thing, but it's not the same effort.
Furthermore, if a task requires only one person to do, and one person has been appointed to do it, a second person is really superfluous. It's great that they want to do it, but not strictly necessary.
Hold this thought.
Angels in Jewish thought have no free will (no Enoch and the rebellious angels, sorry). [My wife would like to add that there are some early minority exceptional traditions regarding this.] In contrast, man has free will. The Torah was given to man, because the service of the angels is not Torah; without the ability to choose to fulfill the commandments, there can be no reward for doing so.
Free will is given to allow you to choose the right from the wrong. But life is a series of parts that don't fit together exactly. Some times you will have to choose one path over another, or even one moral choice over another, both seemingly right. If the path is not obvious, can God justify reward and punishment for man choosing incorrectly from a state of confusion, when that's the natural state of man?
There may be absolute rights and wrongs, but there are many right paths to fulfilling the Torah. If one person especially devotes himself to charity, while another to study, they are both doing the right thing (so long as they both do some of each).
So we see that there is room for latitude for choice and for decisions. The guideline's for your choices come down to the fact that you should always hold in your mind both the fear of God (some say awe of God) and the love of God as your determining factors.
There is, however, a stream of Jewish thought that argues that this is only a lower form of service.
In their argument, real service to God is doing so simply because you were commanded to do so. In other words, fear of God is a low service, love of God is a higher service, but no feeling whatsoever is the highest service.
This type of person walks around as follows: "I'm eating this fruit because God commanded me to have strength. I'm paying money for this item because God commanded me to follow the laws of the land. I'm going to the bathroom because God commanded me to keep my body healthy."
According to this philosophy, there is no thought of reward or punishment for doing or not doing these things, only that one was commanded.
The problem with this attitude is that there are two types of things that do exactly what they are commanded, with no thought of reward or punishment: robots and angels. Neither of which I aspire to be, nor do I think this is a good aspiration for any human.
But there is, indeed, a paradox here.
If one does things for reward and punishment, it's not exactly altruistic, it's self-serving. Surely one cannot be entirely pure and holy for that type of service. On the other hand, if one does something as if there is no reward and punishment, like a robot, then it's not really acting out of free will anymore. Well, they're freely giving up their free will, yes, but still.
I think the answer lies in how I treat my children.
I love my children, and when I do things for them out of love, it is not in the expectation that I will receive anything in return. And even if there are absolutely worse and better ways to parent, there is no single right way.
I am also in awe of the responsibility of a life that I hold in my hands, and some of my choices are guided by the fear of hurting another human being for life. I both accept the responsibility that I have for them - I am commanded to continue parenting them - and I freely do it.
A parallel example could be the way we love and respect our elderly parents.
That, it seems to me, is the correct attitude toward serving God. Not unfeeling, and not for the sake of reward.