The practical element of the subject is taken care of.
The practical element is the part of a subject that is useful in the real world. If something is practical, it is useful. For example, math is very practical because people use numbers for everything. In English, the practical element would be writing and reading. Some people might think that reading novels is not practical because it is not needed in real life.
You need to have an incentive.
When you have an incentive, you have a reason to do something. For example, you might have an incentive to lose weight so you can get a boyfriend or girlfriend. On the job, someone might have an incentive to work hard so they get a raise or promotion. A student might have an incentive to study hard so they can get a good test score in class.
In the long run, everything balances out.
The long run means lots of time, or many days, months or years. When you talk about the long run, you talk about results in the far future. For example, if you eat only fast food, in the long run, you will be unhealthy. In the short term, you might stay healthy, but in the long run, you will have bad health. Also, if you never save any money, in the long run you might be poor. The opposite of the long run is the short term.
Everything balances out
When things balance out, they become equal. For example, in you buy your friend lunch on Monday, then she owes you lunch on another day. So, if your friend buys you lunch on Tuesday, then things balance out.
We are short of religious education teachers.
Religious education is the study of religion, such as Islam, Christianity, Buddhism, and so on. Usually, when people talk about religious education, they mean the study of all religions, not just one.
You are going to get the pendulum swinging
the other way.
A pendulum is something that hangs down and swings back and forth. It swings one way and stops, and then swings the other way and stops and keeps going. When we talk of the pendulum swinging one way, we mean one feeling or action becomes stronger over time and then weaker over time. For example, Monica says that for awhile some subjects will be in demand, so the pendulum will swing that way, but over time, those subjects will not be in demand so the pendulum will swing the other way again.