At some point, I began to wonder whether my Christian beliefs were justified. It pushed me into a quest for knowledge on the matter lasting nearly 3 years. All Christians doubt at one time or another, but it took that long to satisfy my wonder.
I dismantled my beliefs and started to rebuild from the bottom up using deductive reasoning. That is, if a premise can be proven true, then certain other truths must logically follow, regardless of whether or not we like them. e.g. If there is a shadow, we can deduce a light source is shining behind it at some distance.
In the end, I was satisfied and broke my findings down in the following way. First I'll prove that God exists regardless of who specifically that God is—but afterward, I'll prove that God is indeed the Christian god.
We can begin by observing what physicists universally recognize as the laws of entropy. In layman's terms, there are two facets of entropy. One deals with the finite amount of usable energy in the universe. The other deals with the evident reality that all things are moving from order to disorder. Regarding the former, the fact that energy in the universe is finite and running out is proof that the universe had a beginning and did not exist eternally—that is, if the universe was eternal, then the energy in the universe would have already run out a long time ago. Therefore, we can deduce that the universe had a beginning. But what was that beginning like? To answer that, we turn to the second facet of entropy. The fact that all things move from order to disorder is proof that at one point there was a high degree of order, which means all things must have had a beginning with perfect order. Plants, organisms of various kinds, humans, and animals were all created in the form that they exist in today. The fact that all life and structures in the universe are moving from order to disorder is proof that macro (Darwinian) evolution is impossible—structures and life cannot spontaneously evolve toward order out of chaos with no guidance—it would contradict this second facet of entropy. Therefore, the only other option left is that a personal supreme being created all things whole as they exist today, at some point in the past. In summary, God created in a beginning, and He created all things just as we see them today.
The question begged now is, who is this God, and does He care about us as the bible says? There is evidence that this God does indeed care about us. Built into our physical bodies are natural mechanisms for healing. When we get a cut it will heal. Our bodies have built-in capabilities to heal these and a variety of other ailments. Though we cannot regenerate organs and limbs like some other lifeforms for whatever reason, God did instill in our bodies these healing mechanisms. This God must care about us if he built these functions into our bodies. Furthermore, our conscience (the natural sense of right and wrong) which is not even a material entity, is evidence that this God cares about us. Different people in different geographical locations in times past had moral laws and codes, without which they would not have flourished, but would have destroyed themselves in anarchy—societies need laws to thrive. There were penalties and/or negative consequences for lying, stealing, murdering, and committing adultery, just as there are today. Where did they get these laws and why are these laws universal? The first people created may have received the laws directly from God who then passed them down verbally, or the laws could have been instilled in individuals directly from God. In Either case, the universal moral code written in our minds is another proof that this God (whoever He is) cares about us.
So now that we've established God's existence and that he's a caring God, the next question begged is which religion of today most accurately describes God? Not all religions can be right, but there is sufficient evidence Christianity yields the true description of who God is. To better understand Christianity, one must go back to about 1500 years before Christ to the time of Abraham through whom God gave rise to the nation of Israel (the Jews) and a system of foreshadowing and prophecy eventually yielding Jesus Christ, the foundation of Christianity. Christianity is essentially completed Judaism. The nation of Isreal expected Jesus Christ to come because it was written of in the scriptures long before He came (this is evident in the Dead Sea Scrolls which were preserved and prove the old testament scriptures existed before Jesus), but when Jesus finally did come, Isreal as a whole was entangled in idolatry and they did not accept Jesus as the messiah which is why today Judaism still exists. Israel as a nation did not accept Jesus as the messiah (although many individual Israelites did accept Him) and instead delivered Him to the Roman procurator Pontius Pilote who had Jesus crucified. The question to ask here is WHY did thousands of individual jews accept Jesus as the messiah? Judaism was generally a strict way of approaching God and for somebody to claim a man was the messiah sent by God as promised in the Old Testament scriptures, it would have been blasphemy if it wasn't true. Furthermore, it was generally forbidden in Jewish tradition to mingle with gentiles (non-jews), but at the same time thousands of Jews accepted Jesus as the messiah, they also began affiliating themselves with gentiles. The 1st-century historian Josephus, who was not sympathetic to the Christian way, wrote this concerning Jesus: "At this time there was a wise man who was called Jesus. And his conduct was good, and [he] was known to be virtuous. And many people from among the Jews and the other nations became his disciples. Pilate condemned him to be crucified and to die. And those who had become his disciples did not abandon his discipleship. They reported that he had appeared to them three days after his crucifixion and that he was alive. Accordingly, he was perhaps the Messiah concerning whom the prophets have recounted wonders."
What happened to compel thousands of Jews adhering to strict worship of God to quit their way to follow a new covenant laid out by Jesus Christ, as well as unite with gentiles under one purpose? The historical record that Jesus was crucified is well-documented, but why follow a man who was merely seized and put to death? The only compelling event is that Jesus must have risen from the dead, just like the new testament scriptures say. Keep in mind that Jesus' resurrection is not the only proof God exists, although it is indeed proof. The fact the universe exists and that all life was created whole (not evolved) as it exists today, is proof God exists; however, Jesus' resurrection was God's affirmation that Jesus was God (one of the Trinity) had the authority of God, and the authority to forgive and give eternal life. If God can create the universe and life, He can certainly raise a man from the dead.
So now what? Jesus was raised from the dead, but what are we doing here almost 2000 years later? It can seem discouraging and cause doubts since Jesus has not returned, but there are some reasons for His timing. Some of the following verses in the New Testament (my favorite) bring light to the situation. 2 Peter 3 says, "But, beloved, do not be ignorant of this one thing, that with the Lord one day is as a thousand years, and a thousand years as one day. The Lord is not slow concerning His promise, as some count slowness. But He is patient with us, because He does not want any to perish, but all to come to repentance." Some people come to Jesus later in life than others, some who have not been born yet will eventually come to Jesus—God is waiting for them—it's not all about us in the present. Acts 17:26 says, "God has appointed fixed times and boundaries for people so that they might seek Him..." Here we see that God literally sets up the geographic boundaries and the times people will live so that they have an opportunity to seek him. For those who live in relatively desolate areas in the world, God can reach them, although since God is all-knowing He could set up boundaries in such a way that is absolutely just; God knows the heart of all, and some nomads would not want God even if He presented himself to Him. In Acts 1:11, when the two angels speak to the disciples who witness Jesus ascending to Heaven they say, "why do you stand here looking into the sky? This same Jesus, who has been taken from you into heaven, will come back in the same way you have seen him go into heaven." The emphasis here is that He is coming back! Peter 1:8 says, "Though you have not seen him, you love him. Though you do not now see him, you believe in him and rejoice with joy that is inexpressible and filled with glory." There's an implication here that even though we can't see Jesus now, it doesn't mean He doesn't exist or that He's not coming back. Last but not least, prophecy is unfolding before our eyes. The bible says in the last days Israel will be the epicenter of major world affairs. At this moment, Israel is attempting to rebuild the temple that existed during Jesus' time but was destroyed by Romans in 70 AD. The new testament, in various places, says a deceptive world leader (the antichrist) will sit in that temple and proclaim himself as God.