It's easy to confuse the human personality with the soul, but the two are quite different as evidenced by the many lifetimes and different personalities a soul is believed to assume, according to common reincarnation theory.
In Hinduism (and many other beliefs of reincarnation), the act of suicide is a failure of the soul to resolve a karmic entanglement and learn the lessons that would achieve an evolved spiritual state of being.
At Near-Death: The writer of this article explains how Christians supposedly misunderstood the resurrection, and that the resurrection story actually represents the idea of the reincarnation of the spirit.
Reincarnation.ws: This Web site covers a list of what some people consider to be evidence that supports reincarnation as found in the New Testament, the Old Testament and even the Jewish Kabbalah.
While there are many subtle variations among the different religions that incorporate reincarnation, when it comes to the subject of reincarnation and suicide, they share a high-level commonality.