Heaven
Heaven (devaloka or sagga) is one of the six states beings can take rebirth in, the others being the human realm, the animal realm, the realm of jealous spirits, the realm of hungry spirits and purgatory. Heaven is a realm or state that is primarily pleasant and where the lifespan is very long. Buddhism recognizes seven heavens – (1) the Cātumahārājika Heaven, (2) the Tāvatiṃsa Heaven, (3) the Heaven of Yāma, (4) the Tusita Heaven, (5) the Nimmānaratī Heaven, (6) the Paranimmita Heaven and (7) the Brahma heaven. All the heavens were believed to have different spheres within them. These heavens and their various subdivisions are perhaps equivalent to the nine angelic realms of Christian theology, and the celestial beings that inhabit them are similar to the Christian seraphims, cherubims, thrones, archangels and angels. People who have developed positive emotions to a high degree – kindliness, acceptance, innocence, love – without necessarily being very wise, tend to be reborn in one or the other heavens. However, the Buddha said one should be ‘turned off, repelled and disgusted’ (aṭṭiyeyyātha, harāyeyyātha, jiguccheyyātha) by the idea of practising the Dhamma just for the purpose of being reborn in heaven (A.I,115). While heaven is far better than purgatory or the realms of animals, jealous spirits or hungry spirits, the Buddha considered it to be inferior to the human realm. Because their experience is so pleasurable, beings in the heaven realm have neither the opportunity nor the encouragement to develop virtue or understanding. And, of course, when their lifespan comes to an end (like all states, heaven is impermanent) they will be reborn yet again.
The Gods in Early Buddhism, M. M. Marasinghe,1976.