Why do all the credits and debits in accounting have to be equal?

All credits and debits in accounting have to be equal because they are all expressions of the following basic equations:

Assets = Liabilities + Equity

Debts reflect the way in which assets are affected by the activity of a business, and credits reflect the way in which liabilities and equity are affected by those same activities. This may seem not to be the case due to the use of temporary accounts (where revenues are credits and expenses are debits), but the closing procedure reconciles what a business has done with the fundamental accounting equation. Since accounting expresses what is owned and who owns it, the value accounted for needs to be the same in valuing what a business has and who owns what portion of that amount.