Whether Buddhism is a religion is a subjective thing and is
debateable, but it is not a religion under the common understanding
of religion as a belief system that worships God(s)/deities/higher
powers, or as Beyond Religion said,
Indeed, Buddhism is beyond preaching and scaring people into
conversion. Buddhism is beyond claiming that MY God is real and all
others are not. Buddhism is beyond surrendering your individuality
for the supplication and appeasement of a deity. Buddhism is beyond
dividing fellow humans into believers and unbelievers. Buddhism is
beyond dogma and faith.
In short, Buddhism is beyond religion.
But does Buddhism deal with the spiritual? Yes.
"Buddhism has the characteristics of what would be
expected in a cosmic religion for the future: it transcends a
personal God, avoids dogmas and theology; it covers both the natural &
spiritual, and it is based on a religious sense aspiring from the
experience of all things, natural and spiritual, as a meaningful
unity" -- Albert Einstein [1954, from Albert
Einstein: The Human Side, edited by Helen Dukas and Banesh Hoffman,
Princeton University Press]
Karma does not work like 'I am rewarded by Buddha for doing this
or that'. Therefore karma may not be considered as a religious
idea, in a sense.
Buddha has no control over your karma (there are a few things that
is not under
a fully enlightened Buddha's power to control, among them is your
karma, or to grant people enlightenment and so on...), he can only
advise you not to do foolish things, and he can advise you what to
do about them. (i.e we can do something about our unwholesome karma
through insight, virtuous action, etc). It is rather like a
universal, natural law of cause and effect. Karma is action, doing,
intent, and Karma constitutes three basic kinds: intentional
Action, Speech and Thoughts. These results in karmic potential
which ripens on right conditions. In deep meditation one will be
able to see the workings of karma. I am only a novice practitioner
so I don't know much, but there are others who know much more/are
more experienced. True meditators will realise that the power of
karma/volition in our conciousness influencing and manifesting in
our life cannot be underestimated. When external stimulus
(conditions) are present, latent karmic seeds in our consciousness
ripen into effect. Karmic patterns can also draw us to specific
experiences and things.
Nevertheless there are many things cannot be understood at our
level, for example the exact results of karma is one of the four
imponderables, often what one can get is a undoubtable glimpse of
its workings, but unless one is omniscient not everything can be
understood yet... So wait till I attain Buddhahood then I tell you
more. 
Or if you
attain Buddhahood first, tell me.
But one must have confidence and faith in the Triple Gems (Buddha,
Dharma, Sangha) to lead him to enlightenment, otherwise one would
not undertake this spiritual journey to find out for himself.
Certain level of healthy doubting is permissable and even necessary
in certain case if if certain beliefs hinders seeing our true
nature, usually our long held perception and understandings of
things which we are deeply attached.
----
From a previous post of mine, which I said the 3
requirements for enlightenment:
http://www2.bc.cc.ca.us/resperic/science_and_spirituality.htm
Great faith in Zen practice refers to a trust in the process, as
demonstrated by the many who have gone on before, as well as a firm
trust in ones capabilities to see the essential nature of reality
for oneself. In scientific work, great faith refers to a trust in
the scientific method, successfully applied by scientists of the
past, as well as an underlying belief in ones inherent capability
to understand the phenomena being studied.
Great doubt in Zen refers to a willingness to profoundly question
all of ones most cherished beliefs, and ultimately to uproot them.
Beliefs are but concepts, floating on the surface. The conceptual
realm may be useful at times, but compulsive attachment to
particular concepts is a hindrance to penetrating to deeper levels
of realization of the fundamental nature of reality, which is
beyond all concepts. An ancient Chinese saying states that when a
wise man points his finger to the moon, the fool sees only his
finger. In science, great doubt is based on a realization that
the model is not the reality. Being too attached to a particular
hypothesis or theory can prevent one from arriving at a better
theory that reflects a deeper understanding of the phenomena of
interest.
Great determination in Zen is required in order to not give in to
laziness. The process may take some time, and without determination
one may never attain deep realization. In fact, there is no deepest
realization, and only by great determination will one keep going
deeper. Of course the same can be said of scientific research.
------------------------
p.s If anyone finds any error in my post please correct me.
