Seneca tells us that life is long enough if we make the most of it.
A Course In Miracles teaches that the purpose of life is to accept the Atonement for ourselves and to share it with others. The Atonement is the recognition that we made a mistake in believing that we could separate ourselves from the nondualistic Oneness of God, or the Tao, or the Spirit of Life, or the Higher Power, however you understand it.
Unitarian Universalists covenant together to affirm and promote the respect for the interdependent web of existence which (of course) we are a part. Some people come to appreciate, understand, and become grateful for this respect and others never seem to become aware of it.
The good life, as Seneca reminds us, is to invest our awareness and energy in envisioning the best that is in us and in others or as UUs name it, "the inherent worth and dignity of every person."