If you believe in Reincarnation:

 Then you can likely at some point access some or all of your lifetimes in the past, present and future.

How?

Because your soul doesn't live naturally in time and space. It only lives in time and space while you are alive in a physical body here on earth or in some other dimension or planet in this galaxy or another.

So, the karma (both good and bad) that you are experiencing right now is tied to the past, present and future lifetimes that you as a soul could access if it is useful for you to.

The problem becomes (I have found) the traumas not only of this lifetime but of others as well.

For example, if you were tortured or beheaded or things like this in other past, present or future lifetimes you really do not want to experience that again for a variety of reasons.

So, what I do is to give this prayer to fix this problem:

Dear God:

Please show me what I need to know about my past, present or future lifetimes that you think it would be helpful for me to know about. I don't want to re-experience horrible deaths or physical ailments in the past, present or future. But, what will help me become enlightened so I can better help myself and others right now in this lifetime?

Thank you, God for all your help in all my lifetimes past, present and future.

Amen.