Suppose we assume there is a cosmic war between good and evil. In light of such a war, spirits on the side of evil can create unique experiences of the sort described in favor of reincarnation that does not result in a unique identity.
If spiritual identity is translated as reincarnation, Jesus, who is explicitly referred to as the Second Adam in the Bible can be regarded as reincarnation of the First Adam.
Reincarnation is with respect to function or purpose however not identity.
Jesus succeeded where Adam failed even though both were born directly of God.
In the Bible a prophet Elisha received a double portion of the spirit of his predecessor, implying identicity of spirit yet differed significantly in character, personality, strategy of office etc. from his predecessor. Spirit was the same yet there was uniqueness of identity.
Christianity makes no assertions about reincarnation. In principle however the Bible makes clear that identity always is unique in the event the same spirit is at play in a different person or body for achievement of an objective at which someone else had failed in the past.
Within Christian doctrine, to be born on earth is a good thing because birth signifies good purpose from God. Every newborn can choose however to reject God’s good purpose in favor of offers of riches, popularity, fame etc. from the devil. The world is an evil place then because newborns choose to reincarnate evil spirits as opposed to the Spirit of God. Suffering does not originate from God but from people’s choice of evil over good. When people rail against God sometimes it is because they decry their God-given power of choice as they are unable to use it for good.
If ever we thought newborns were innocent, we ever were deeply wrong.
When even one newborn chooses God’s Spirit like Moses must have, the whole world order can be turned on its head for good.
Oh the power for good in this life of one person who chooses love, life, light, wealth, and peace over hatred, love of money, darkness, and strife.