article from:  http://www.ukapologetics.net/canyoushow.htm 

There are two distinct questions here, and and the second follows logically from the first. But before we start, we need to resolve a background issue.

In asking this question, we're basically asking "What kind of proof will be good enough? How much proof is needed?". When we talk about proof, we're talking about establishing some degree of certainty about something.

Scientific knowledge is based on repeated observations, but scientific knowledge is only one kind of knowledge. Other kinds include historical knowledge, philosophical knowledge, moral knowledge and personal knowledge. These types of knowledge lie outside the bounds of scientific knowledge.

For example, take historical knowledge. Can you prove that King Henry the Eighth existed? Using the scientific approach of observation and repeatable experiments, impossible! But using historical methods, it is certain that he existed beyond a reasonable doubt. This phrase is the key. While not one person living today has ever seen King Henry the Eighth, we know he existed beyond a reasonable doubt. This is why in law courts, a jury must be convinced of guilt beyond a reasonable doubt, not beyond a shadow of a doubt.

So, when we look to prove whether God exists today, a scientific approach will not work. The amount of proof needed is enough so that we can say: "God exists beyond a reasonable doubt".

We can now restate the two questions above:

Is it reasonable to accept that there is a 'Higher Being' behind this universe? If so, how do we know 'what' or 'who' the Higher Being is? Is There A Higher Being?

There are many different arguments for the existence of a Higher Being, none of which rely on the Bible, and none of which can be scientifically proved. Here are a few:

When we look at anything which has a design, we rightly conclude that it had a designer. Somebody designed chairs for a purpose. Somebody designed a glove to fit over a hand. The universe, and particularly human beings, show an unbelievable amount of design. This points to a Designer.

Humans have a complex personality. It seems (and is) absurd that such complexity could have emerged from nothing, with no cause. Rather, the human personality would need to be made by a Being with the same, if not greater, complex personality.

Everything we can think of, and which we encounter, has been caused by something. Every effect has a cause. In something as complex and awesome as the universe, there is no difference. The Big Bang Theory does not destroy this argument, for no-one can explain the cause of the Big Bang.

If there is a concept of something, this implies that the something does exist. For example, there is the popular concept of 'true love'. Although this concept might often seem elusive, the fact that we have the concept of true love in our heads, points to the real probability of the existence of true love.

The sense of morals which most people have 'built-in', points to the existence of a moral Maker. More than this, the other option of evolution, has no way of explaining how morals came from pond-slime, and ultimately, from nothing.
These arguments, on their own, and even collectively, cannot possibly 'prove' that God exists. However, they provide enough of a starting point to accept that there is probably a Higher Being of some kind. At this point, we are in a position to try and answer the second question.

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