Reincarnation is the teaching that a person’s soul, after death, goes to a holding place and after a while enters a new human body. This cycle continues over and over again for thousands of years until the person learns what needs to be learned, and then the reincarnation process ceases.
A Christian who believes the Bible should not believe in reincarnation. The Bible tells us in Hebrews 9:27 that it is appointed to men to die once. After this comes judgment. Reincarnation would contradict this teaching. Therefore, reincarnation is not true, and Christians should not believe in it.