I'd like to take this in a slightly different direction. The Baal HaTanya also talks about how since we know that HaShem's kindness is infinite, so we know that all of His attributes are similarly infinite. From here he explains how it is that HaShem's Gevurah is able to hide and contain his Hesed, his kindness, when it isn't called for. Since HaShem's Gevurah is also infinite, it can hold back HaShem's infinite kindness.
Now, I'd like to learn about the rest of the Berachoth in the Amidah, the Shemonah Esrei, from what the Baal HaTanya taught yesterday about the berachah of סלח לנו - forgive us. Just as we say that HaShem forgives us immediately after our asking him to, so too we must learn the other berachoth similarly: When we ask HaShem for healing, for beracha/rain/livelihood, for the ingathering of the exiles, for the rebuilding of the Jerusalem and the Beit HaMikdash, for the coming of ben David, for the answering of our prayers, for the return of His Divine Presence to Zion, for bringing peace to Israel, etc. when we ask HaShem for any of these, we also must know that He grants them immediately.
We have to bring ourselves around to this understanding, we have to come to this level of emunah, just as we need to understand and truly believe that HaShem forgives us completely as soon as we ask it of Him.
One might say "this sounds nice, but that isn't the way the world works." Isn't it? How much of a difference does one's expectations and perceptions have on the outcome of one's efforts? When people (especially children who lack the learned cynicism of adulthood) expect to recover from illness, medical treatments are far more effective. When people lack confidence they fail far more often. When people think something is impossible they give up far more quickly. When people are empowered by faith in themselves and others' faith in them, they accomplish exponentially more.
How do we know it isn't us holding ourselves back? Look to the story of the meraglim. How do we know HaShem's hands aren't open to give us every single thing that we could possibly want or need and it that it isn't just us and our lack of faith getting in the way?
Oh wait, it is just us, because HaShem tells us Himself that the evil never comes from My mouth.
HaShem waits with open arms all day every day for us to jump into them, to say "Abba, protect us, help us, save us."
There is a principle of berachoth in which we say הכל הולך אחר החתימה - everything goes according to the seal. The normal understanding of this is that the most important part of the berachah is the end--it's not complete until the end defines where the berachah is really going. But, we can also read it: everything goes after the seal. After the berachah is already sealed and done, that's where all the challenge comes in. We have to be ready to receive the berachah, if we aren't then all the berachoth in the world won't help us.