There are three reasons why we need to study and practice the teachings of Buddha:
To develop our wisdom
If we do not strive to develop our wisdom, we shall always remain ignorant of ultimate truth – the true nature of reality. Although we wish for happiness, our ignorance leads us to engage in non-virtuous actions, which are the main cause of all our suffering.
To cultivate a good heart
If we do not cultivate a good heart, our selfish motivation destroys harmony and good relationships with others. We have no peace, and no chance to gain pure happiness. Without inner peace, outer peace is impossible.
To maintain a peaceful state of mind
If we do not maintain a peaceful state of mind we are not happy even if we have ideal conditions. On the other hand, when our mind is peaceful we are happy even if our external conditions are unpleasant.