|Smile, there may be many hells and heavens yet no "God" due to workings of karma.|
|Stephen Batchelor - atheist|
|The Buddha surrounded by humans and devas|
Therefore, if theism includes the belief in "gods" (devas or "shining light beings" superior to humans in happiness, beauty, longevity, and other qualities), then the Buddha was no atheist.
The Buddha pointed out the wrong-view of relying on an all-powerful God as an explanation for the universe, karma, or as a means to enlightenment and final liberation from suffering.
|Buddha in Thailand (Dongissel/flickr.com)|
There are worlds in space, "heavenly" planes, some subtle (rupa), some immaterial (arupa). But even in this Sensual Sphere (kama loka), there are better planes/worlds to be reborn in.
Therefore, there is sex after death, sex in lower "heavenly worlds." In the world of Brahma -- which transcends sex, sensuality, and sexual dimorphism (Great Brahma and the other Gods being neither male nor female) -- is peaceful and sublime. But it is no final end of suffering, no escape from the round of rebirth or karmic results. It is no solution to the problem of ignorance and the suffering it brings about.
Enlightenment is a solution.
The Buddha was not a god, prophet, avatar, or an advocate for the gods/God. Instead, he demonstrated what an ordinary human being can attain in terms of wisdom, compassion, and most importantly a liberation surpassing that of God/the gods. He is therefore regarded as a teacher of devas, brahmas, and human beings.