The past is already gone, the future is not yet here. There’s only one moment for you to live, and that is the present moment.
There is no path to happiness: happiness is the path.
Since this is a forum for ideas expressed in the written word, please let me indulge in a bit of quibble here. Strictly speaking, there is a difference between Nirvana and Enlightenment. Nirvana means the escape from the cycle of reincarnation and is part of the Brahman cultural/religious tradition. Most of the people to whom the Buddha preached would have been raised in that tradition and thus would have been familiar with Nirvana. The same way that today a Buddhist preaching to Christians would make analogies of the Mystic Law to God, the Buddha would have made analogies of the freedom of Enlightenment to Nirvana. However, analogies are preparatory teachings, not essential teachings. The essential teaching is expressed by the quotes shown above. Life, like the universe itself which is imbued with life, is eternal. We all have had infinite numbers of past lives and will have infinite numbers of future lives. What is always of infinite importance, then, is this moment; and the virtuous happiness derived from this realization is Enlightenment.