If you do not believe exactly what the Bible says about creation you have been at least partially deceived by the Enemy.   

As unbelievers began to realize that 5 billion years is not enough time to enable the impossible event of life coming from non-life much less the varieties of organisms, they came up with the theory of multi-verses to provide more opportunities for the impossible to actually happen.   

The powers of imagination are impressive but they are nothing in comparison to the Truth.   

In the beginning God.   

This is the believer's foundational assumption which is necessary and sufficient to explain creation.   

To understand why He created and where creation is headed we need to know His Word - the Bible.   So, the second most important assumption is that the Bible is the Word of God.   

To reject God is to remain ignorant of who.   
To reject the Bible is to remain ignorant of why.   

The ignorant are left only to puzzle over how.   Such are searching for knowledge where it cannot be found.   No one can go back to the beginning.   No one can test a theory of creation.   It is an exercise in futility if one is interested in Truth.   

If one is interested only in science fiction, they can derive some transient pleasure from their mental gymnastics.   

Which camp are you in?