Reincarnation is taken seriously by millions and millions of Hindus and Buddhists all over the world, and more and more Americans are ascribing to this worldview as well
In Hinduism, Samsara is the "continuous flow", as souls originated from the collective oneness of God's consciousness, known as the Brahman. After enduring a cycle of birth and rebirth, each soul is to learn from his or her karma, thus being perfected from its journey through successive lives, on its path back to the Brahman.
Similarly, the Bible speaks of the God of Abraham, and like the 'Brahman', all things came from Him, and all things are to return to Him. The nation of Israel are as the collective body of Jacob, and each time they have gone from slavery to freedom, or from exile to reestablishing their kingdom in Israel, they have paid for their bad karma, and have sought Moksha, the freedom of the soul, to find oneness with God.
For this reason, Jesus tells us to be "Born Again", as in him, we are freed from this cycle and given Eternal Life.