What is the key belief or principle that he states in his speech?

Without specific context about which speech you are referring to, I can only provide a general answer. Typically, key beliefs or principles in speeches often revolve around themes such as unity, resilience, the importance of justice, or the power of hope. The speaker may emphasize the need for collective action or individual responsibility to address societal challenges. To provide a more precise answer, please specify the speech or speaker in question.