Rav Itamar Shwartz, the author of the Bilvavi and the Getting to Know Yourself (Soul, Emotions, Home) seforim has a free download available of Shavous Talks here.
We find three times where the Torah refers to counting: counting the years to Yovel (the jubilee), counting the days for purification of a zavah (VaYikra 15:19), and counting the omer. But a zavah does not make a beracha when she counts. Tosfot (Menachot 65b) explain that with the omer, we can be sure that it will lead to completion, but the zavah might not become pure at this time.
With the omer, then, we are able to begin (and continue) with an awareness of the end. If we do not anticipate an end, there is no blessing (and no requirement to count orally, which is why the zavah need not count orally). In life, too, we must always maintain an awareness of the end, as the Rosh writes that one must always be cognizant of death.
We might ask: Chazal have taught us (Avot 2:16) that “you are not expected to finish the task.” How, then, can one keep the end in mind if he will never reach the end?
If a person is ill, and there is no known remedy for his illness, that does not necessarily mean that he should despair of being cured. Often, there is ongoing research, and a cure might be discovered at a later time. He may want to begin saving his money for when it will hopefully become available. So, too, although one individual cannot single-handedly cause Mashiach to come, he should anticipate that it will come soon, and focus his actions toward that endpoint. Inwardly, a person must always yearn for that goal.
The value of this yearning is that he will have a completely different perspective on his actions. For example, if a person plans to move to a nicer home as soon as he can afford to, he will not invest more money in his current home than absolutely necessary. The opposite will be the case with someone who plans to stay in his home for many years. So, too, if we focus on the end (the times of Mashiach or our own deaths) our attitude toward this life and this world will be much different than if we were focused solely on our current state. We would be much less focused on material things. We would still take care of our needs here, but be aware that it is all temporary.
A person would not invest all his money in something unstable. Chazal in fact have advised that one divide his assets among cash, land, and merchandise. This world is unstable, and we must be aware of this fact not only with regard to money.
To illustrate: A person at a red light would not turn off his car engine, because he expects to move soon. But I was once in a traffic jam because the police stopped traffic for hours while they were looking for a criminal, and people parked their cars in the street and got out while they waited. Life is more like a car at a red light. We must be ready for any change in life. This world is full of drastic changes.
These changes in the world serve to remind us not to take the material world too seriously. We must focus on what has real permanence. For example, when a person seeks a wife, he is very careful, and he would not marry someone unstable, because marriage is a long-term commitment.
What has permanence here is the spiritual level. If a person seeks truth and stability, he must be aware of the instability of this world, and not take it too seriously, and on the other hand, connect to the permanent world of Hashem and the Torah. These relate to the eternal world. This awareness will enable us to accept the Torah properly on Shavuot and earn eternity.