One objection to arguments for the existence of God like the cosmolgical, teleological, or axiological arguments, is that these don’t necessarily show the existence of the Christian God (i.e. the Trinitarian God of the Old and New Testaments of the Bible). That’s true, they don’t. but these arguments do lead you to the necessary existence of a first cause, a supreme designer, and a moral lawgiver – roles all fulfilled by the Being described in the Bible as God. That is a huge step in the right direction. Once you’ve gotten over that big hurdle of admitting that God does (and must) exist, the journey to becoming a Christian can be as short or long as you make it. Sometimes we like to take the long way (just to satisfy ourselves, I suppose), but even if you investigate all the world religions first, a sincere pursuit of truth will lead you back to the God of the Bible.
Now, none of those arguments for God’s existence rely on the Bible. They are all separate lines of philosophical reasoning, pointing to the same conclusion, but they don’t use the most direct explanation of the origins of the universe, life, and morality – the testimony of the Bible. That’s because there are two different sides to God’s revealing of His truth: general revelation and special revelation. General revelation is what He reveals of Himself and His actions in the world around us. That’s why it’s also called “natural theology.” Special revelation is the record we have of God speaking directly to humankind through various chosen people throughout history, and most importantly, through the Incarnation of Jesus Christ. These two approaches to revealed truth are like the difference between forensics and testimony. You might try to piece together who left some incredible surprise gift on your porch from the little bits of evidence you can scrape together. You may be able to narrow down the list of suspects from the large shoe size tracks leading up to the porch, or some other forensic clues. But if you received a letter in the mail the next day from your good friend explaining that it was from him and why he did it, wouldn’t that simplify things tremendously? The Bible is that letter explaining everything!
Or consider this example from my engineering job. The American Institute of Steel Construction publishes a rather hefty little book every so often that’s commonly just known as “the steel manual”. It’s filled with all kinds of good information relating to steel design, and I reference it nearly every day for something or other. If I couldn’t remember the formula for deflection of a beam, for instance, would I have to have that book? No, I could do an experiment with a stick over 2 supports with different weights hanging in the middle, and eventually work out the relationship between loading and deflection of beams. But it would likely take me a while, and probably wouldn’t be very exact. Or I could look in Table 3-23 and quickly confirm that the deflection of a simply supported, uniformly-loaded beam is (5wL^4)/(384EI). Now, that’s an example of something that I can determine from actual experiment or from simply reading the book. However, there are other things that no amount of experiments will tell me. For example, in design, we use various safety factors to account for variability in real-life conditions, and to provide a somewhat consistent “cushion” in case of accidental (or deliberate) overloading. Can I ever determine that from any experiments? Not really. That’s because these are philosophical reasons. We generally prefer nice, slow, ductile yielding of building framing in the event of a failure rather than sudden, brittle, snapping without warning. The first warns the occupants of the building that something’s wrong, giving them time to evacuate; the latter can result in sudden collapse and many tragic deaths. Therefore, our design philosophy is to favor ductile limits over brittle ones. But that philosophy, and the values of the safety factors we derive from that goal, can only be determined by going to the authoritative source, AISC’s book.
Similarly, there are some general things about Himself that God has revealed in nature, and that we can determine from rational thinking. But for the most part, you need to go to His book. I’ve heard friends say that they would believe if God did something like write “I made you. – God” across the sky, or arranged the stars to say something similar. Ironically, they say they would believe at a rather short, simplistic message, even though God has left a long, detailed message in the form of the Bible. I encourage you to use all the resources available to you; explore both God’s general revelation and special revelation. The world-famous atheist Antony Flew finally had to admit there was a God just from the general revelation of God in the clear design of DNA. Sadly though, it doesn’t appear that he was willing to take the next logical step before he died. Don’t complain of not having enough of a message from God when He has left you His own narrative. He has taken the stand, so to speak, and testified of Himself. Don’t dismiss Him without reading what He has to say.
 AISC Steel Construction Manual, 14th Ed (2010), Commentary on section J.4., p.16.1-413. Also, Commentary on section K2, p. 16.1-427.