The Cosmological Argument - the Key points

The Kalam Cosmological Argument (William Lane Craig) - Aims to prove God as the first cause and personal creator of the Universe

Proving God as the first cause:
Potential infinite  - there will always be a finite number because infinite is impossible. Time is linear because it is always possible to add one more series of events (successful addition - the history of the universe)

Actual infinite - there is an infinite number as time is circular, therefore successive addition cannot exist (numbers cannot be added or subtracted to time because the number remains the same)

Because successive addition exists (the events of history, past & present) than actual infinity must be impossible and potential infinity is real! 

Proving God as the personal creator: If the Universe had a beginning, it must have had a cause rather than no cause because the rules of nature did not exist before the Universe had begun, so there must have been a cause which was either impersonal or personal - God is the personal first cause because he has the ability to will for something to happen

Universe --> no beginning/beginning --> no cause (natural occurrence)/cause --> impersonal/personal

3 of the 5 ways for proving the existence of God as the first cause of the Universe:

The First Way: Argument from motion - God is the efficient cause who caused the potentiality of the universe to be actualised, and is also the Actus Purus (prime mover/pure act) who actualised the Universe for the final cause (reason for the actualisation of the Universe). Motion, is the reduction of potentiality to actuality.

The Second Way: Argument for the uncaused causer - Every effect has a cause and infinite regress is impossible therefore there must be a first cause which is uncaused (God) to explain the existence of the Universe. 

A being cannot precede (cause) itself, therefore there must be an uncaused causer who had necessary existence as an external agent who has the ability to self-cause themselves, in order to cause the Universe into existence. This being must be self-causing and non-contingent. It rejects infinite regress because you cannot have an endless series of caused causes - it has to start somewhere! To deny infinite regress is to accept a first uncaused causer of the Universe!

The Third Way: Argument from contingency

Necessary being (God) - non-contingent, self-causing being who causes contingent beings into existence. Contingent being (natural world) ultimately rely on a necessary being to cause them into existence. Because contingent beings do exist in the natural world (e.g. us humans), than a necessary being must exist who caused them into existence) 

Sufficient reason - an adequate reason that explains the cause of an event

God is the sufficient reason that explains the cause of the existence of the Universe