Hashem took the man and put him in the garden of Eden to work it and guard it.

We can surmise from this verse that there was work to do in the garden of Eden. The first man was put there to work and guard the garden. Besides wondering what kind of guarding was needed when the human population was so small, I also could not figure out who has been working and guarding the garden since the first man was removed from it.

The Ohr Hachaim Hakadosh has a commentary on this verse. He says that there are two kinds of commandments: positive and negative. The man was put in the garden to do commandments and to guard from doing against the commandments.

(The Meshech Hachmoh wrote that there was a positive commandment to eat the permitted fruits and a negative commandment not to eat the forbidden fruits.)

Back then the first man was actually in the garden and could see the effect of his work. Now that Eden is only for souls who have departed from this world, the ones who reach Eden after death will find waiting for them what they prepared for themselves while alive.

In other words, the first man had a big advantage over us. When he did something good, he could see the garden improve. When he did something wrong, he could see the garden deteriorate. This is a fantastic way to improve our service to the creator. However, now that we do not see what we are building or ruining in Eden, we often doubt that what we do has any effect at all.

I saw a very similar idea at the beginning of the parsha: "Hashem saw the light that it was good and Hashem separated between the light and the dark." Of course, the question is that if Hashem thought it was so good, why did he change it? Rashi says that Hashem did not want the light to be used by the evil so he put it aside for the righteous people in the future.

Harav Sternbuch, SHLITA, wrote that light and darkness were to help the first man in his service of the creator. When he did good he was in light and when he did wrong he was in the dark. Hashem did not want the evil people to push their way into the light by occasionally picking some decent thing to do, so He put this light away for the righteous in the future to help them serve Hashem. (This explanation is used to explain the meaning of the song in the Hagaddah that the day is approaching which is neither day nor night.)

Both of the ideas are similar in one way: our good deeds are supposed to give us strength to do more good deeds. We should believe that following the Torah is a way of building for the future in a fine garden with strong spiritual light. We should make a major effort to imagine that everything we do is recorded in order to improve our service of the Creator.