I like this question. Its one that is a "show stopper" for many debates, and the level of knowledge of the debaters will determine on who's side it stops. Let's look at it.
As mentioned in my post "How It All Began- Part 2", people who hold a naturalistic worldview believe that life on earth was planted here by a superior race of aliens. These people are often challenged by pointing out that they have not eliminated the need for God; they've only moved His need back one step. "Who created the aliens?" If they hold to a naturalistic worldview, they are stuck- unless they want to posit another race of aliens created the aliens who planted life on earth. Of course, they could keep going infinitely back in time, and they would never actually explain an ultimate beginning of any life.
Many Naturalists know this, so they throw the question back to us. "Who Created God?" They believe that we are in the same predicament that they are. They anticipate our response of "God is eternal" and are prepared to laugh us down by rhetorically asking, "how can you posit attributes of something that you haven't proven even exists?"
However, the table can be turned on the Naturalist by the Theist who is armed properly. Since Naturalists don't regard the Bible as a reliable source, I won't appeal to it, and neither should the Christian in this position (if he does, the Naturalist will target the Bible as a reliable source rather than the issue- not that they would provide any good evidence, they would just laugh it away, along with the audience). I will appeal to the Bible as a source for the Christian's benefit later in the post, though.
According to the general theory of relativity space, matter, energy, and time came into existence at a single point in the finite past (The Big Bang). The key here is that time itself has a beginning. Keep in mind that "create" is a verb that requires time (creator...some time passes...creation). If time did not exist before the Big Bang, then whatever is out "there" is "time-less". Whatever is out "there" is also "beginning-less" and "end-less". If something has no beginning, it has no need for a beginner (creator).
The cause of the universe caused time, therefore is outside of time, therefore has no beginning, therefore has no beginner. The Christian faith teaches that God is the Cause of the universe; therefore God is outside of time; therefore God has no beginning; therefore God has no beginner.
Not only does the Bible teach that God created the universe, it also teaches that God existed before time existed.
John 1:1-3, "In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made." If creation includes time, then God existed before time.
John 17:24, "Father, I want those you have given me to be with me where I am, and to see my glory, the glory you have given me because you loved me before the creation of the world." God was active before time.
I Corinthians 2:7, "No, we speak of God's secret wisdom, a wisdom that has been hidden and that God destined for our glory before time began." God was active before time.
That list of verses is certainly not comprehensive, but provides a good start for the Christian looking or the non-Christian checking that the Bible actual does teach this.
Here's a quick video from Randall Niles:
For more information:
Beyond the Cosmos- Hugh Ross