Let me start out by saying what works in your essay. The structure of your essay is correct for an academic paper. It is clear that there is an introduction paragraph, three body paragraphs, and a concluding paragraph. I can also see that your three body paragraphs back up your argument, education is important for improving lives. It is good that you have a well-organized paper.
However, there is room for improvement.
Helpful tip: start with a short outline of your essay before you start writing. Your first paragraph is usually where the thesis belongs. A thesis is an argumentative sentence that some people can disagree with. "We would not be able to better our lives and our world without education" is a good start because some people can argue against it. However, it could be stronger if you also included the 'how'. For example, a sentence such as "We would not be able to better our lives and our world without education because education helps us to make better decisions for the future, make improvements in technology, and connect with the rest of the world," would be a stronger thesis because it introduces what you are going to talk about in the rest of the essay. It is important to be as specific as possible when writing papers.
Your body paragraphs would be a lot stronger if you included more specifics. Just one or two extra sentences pointing to a specific situation would be very helpful. For the first body paragraph, you could mention an event in history, such as slavery, that we try not to repeat. Adding points like these make a more interesting paper and provide a stronger argument. Remember that concrete evidence makes you more believable.
Your concluding paragraph is pretty strong because it reiterates your main points in a fresh way.
For an essay that is timed and as short as this one, you could also try to narrow down your topic so that you can be even more specific about it. For example, you could have taken one of the points that you wrote and made a whole essay out of that one point.
Good job and keep it up!