Which statement is true: (1) If someone returns to your life after you have let go, he/she is your friend for life. (2) Friendships are meant to come in and out of our lives.
I think both can be true, actually. Just because someone leaves and then comes back doesn’t mean every friend that leaves will come back, and just because someone leaves and doesn’t come back doesn’t mean no friend ever will. The two definitely aren’t mutually exclusive. The reality is that life changes, which means that it keeps changing. It may change in a way that sends you and a friend in different directions and then bring you back together, only to separate you again. You never know what may happen.
But just because one statement in this case is true doesn’t mean the other is false. Neither are definitive in being true or false, and they can both be true and both be false at the same time.