Many people attracted to the Buddha’s teachings on impermanence and suffering nevertheless have a problem with his teachings on kamma and rebirth and are quick to reject them as outmoded metaphysical ideas, either cultural baggage or interpellations intended to placate his less-sophisticated followers. Here I attempt to show that such doubts are based on misunderstandings and that kamma and rebirth are in fact verifiable through meditation…
If I am not the body, not the feelings, not the mind, then what is it that is liberated?
“Such a question [is] simply doubt arising. When you let go of everything and experience the peace and clarity inherent in that, you don’t have to put a name or identity on it.” – Ajahn Pasanno 
The Buddha is said to have recommended five subjects for frequent recollection:
I am subject to aging, have not gone beyond aging…
I am subject to illness, have not gone beyond illness…
I am subject to death, have not gone beyond death…
I will grow different, separate from all that is dear and appealing to me…
I am the owner of my kamma, heir to my kamma, born of my kamma, related through my kamma, and have my kamma as my arbitrator. Whatever I do, for good or for evil, to that will I fall heir.
The first four recollections relate to the existential fact of impermanence and I don’t imagine anyone having a problem in acknowledging them or in understanding why it’s good to reflect on them. The last recollection might appear to be more problematic, however, and a lot depends upon one’s understanding of the scriptural accounts of Buddha’s teachings on kamma and death and rebirth.
The Buddha said; “Intention, I tell you, is kamma.”  My understanding is, he’s using the word kamma to mean wilful action – that is, any volitional action from the point of view of a ‘self’ that desires to have something, or be something, or get rid of something (due to ignorance of the fact that all dependently arising phenomena eventually cease and are therefore unsatisfactory, without any inherent qualities, not ‘I’ or ‘me’ or ‘mine’).
‘Rebirth’ is the ripening ‘fruit’ or result (vipaka) of kamma – that is to say, intentional action results in yet another delusional experience of ‘I’, ‘me’, ‘mine’ or ‘self’ existing independently of the rest of the world ‘out there’. The aggregates (form, feelings, perceptions, fabrications, awareness) that come together in this momentary ‘rebirth’ experience are themselves ‘void’ or ’empty’ and habitually appropriated (as ‘mine’, something ‘pleasant’ or ‘unpleasant’ or ‘neither pleasant nor unpleasant’ that is happening to ‘me’) even though they are destined to break apart again in a momentary death experience that will condition the next rebirth… and so on. It’s this unsatisfactory lifecycle – without discernible beginning or end – that I understand the Buddha to be referring to when he spoke the First Noble Truth of Dukkha.Ask what happens to ‘me’ after ‘my death’ and almost immediately there’s absorption into some metaphysical world of creative imagination; this is actually ‘rebirth’ in action – a process that’s happening to ‘me’ all the time, as the following simple example illustrates. Stepping outside into the sunshine, “I” perceive “my” experience as pleasant and there is rebirth into a pleasant world. Clouds obscure the sun; “I” begin to worry over whether or not it’s going to rain and immediately the pleasant world dissolves and there is rebirth into an unpleasant world. “I” remember when it rained on “me” only yesterday; the unpleasant world dissolves and there is rebirth into the world of “my” former life and it feels slightly less unpleasant… Continual arising/ being/ cessation of ‘Self’ and ‘The World’ is discernible at many different speeds and subtleties. In other words, there’s no eternal ‘soul’ or spirit personality and nothing or nowhere stable enough for one to reside. At this point we may ask, is it reasonable to suppose that the aggregates constituting a sense of self just vanish at the moment of conventional death like the secularists would have us believe? Could it not be that mental aggregates are recycled elsewhere in the universe like form aggregates (i.e. like molecules and atoms)?
In my opinion, when the Buddha spoke of his ability to recollect “his manifold past lives” and “the passing away and re-appearance of beings” he was not rejecting the extreme views of materialist and annihilationist philosophers for the equally extreme philosophical views of the eternalists and idealists. By speaking of rebirth rather than ‘reincarnation’ he was sticking to his ‘Middle Way’ approach in referring to a verifiable process that is occurring many, many times in the space of a single moment and is without any discernible beginning or end. Look back in time and the aggregates of ‘I’ or ‘me’ or ‘self’ are seen in one’s parents’ and in many other lovable or loathsome historical characters. One’s body is destined to be re-absorbed into the physical lifecycle of future beings. One’s ideas, opinions etc. are destined to be reabsorbed into the mental life cycle of future beings. And the good news according to the Buddha is, this unsatisfactory lifecycle can be broken by cultivating morality, concentration and wisdom. 
The truth of the Buddha’s teachings is to be realised through meditation and mindfulness – it’s not something that’s discoverable through reading and discussion. I try to concentrate on present moment reality rather than get caught up in philosophising. Nevertheless, there are some good similes that can assist a spiritual search for peace of mind.
For example, I find it helpful sometimes to think of the human body as a candle and the mind as a flame fuelled by ignorance, craving and aversion. Moreover, the winds of death are blowing from all directions. Just as a dying candle flame can be a conditioning cause that ignites a new candle flame, so too ‘my’ last dying thought can be a conditioning cause that ignites the initial thought-train of a newborn elsewhere in the universe. In both cases, what is ‘reborn’ is the same but different from what has ‘died’.
My intention throughout the writing of this essay was, as far as possible, to comment only on what has been directly experienced, which is why I stress the mental aspects of kamma and rebirth (mind taken as being “forerunner”) rather than the physical aspects. Having said that, however, I know that certain thoughts can bring about certain physiological changes (angry thoughts causing muscle tension and nausea, for example), and so no matter how unlikely or distasteful the thought I cannot honestly rule out the existence of some causal link between past life kamma and present or future life misfortunes (such as disability or poverty, for example). Much of what is contained in the scriptures remains beyond my current experience or level of understanding. It’s my choice to remain open to such teachings rather than reject them as either ‘fanciful’ or ‘not politically correct’, and my faith is that things will become clearer with more study and practice.
 Ajahn Passanno, The Last Breath (California: Abhayagiri Buddhist Monastery, 2003).
 NB. Not all Buddhists see rebirth as I do! Personal experience inclines me more towards this understanding of The Buddha’s teaching –
“The “present life” is one process of dependent arising in the instant, whereas the “next life” is another process of dependent arising in the next instant. This is a more realistic way of understanding the law of dependent arising. To people who embrace the concept of a continuing existence, however, “birth” comes from the mother’s womb and “death” is physical death. This is using everyday or children’s language and not what the Buddha taught.” Buddhadasa Bhikkhu, ‘Paticcasamuppada: Practical Dependent Origination‘ – in Dhamma Talks.Net
Thanissaro Bhikkhu, ‘The Truth of Rebirth: And Why it Matters for Buddhist Practice’ – in Access to Insight (2013)
Walpola Rahula, What the Buddha Taught, (1959).