Many people don't understand why someone would be a Christian, because Christians follow additional rules, that they are not legally required to and help others, knowing there will be no reward in exchange and helping regardless of whether the person helped is even grateful or a mean person. Christians then talk about how much God gives them and all of these things that they are are given are abstract ideas (values) and a promise of eternal life, which both have little meaning, to a dishonest and carnal generation or society.
Why would anyone want to follow a rule they didn't have to? Why would anyone take time to exercise or eat less food, if they didn't have to? The answer to both questions is that denying yourself short term pleasure can give you long term happiness. The other thing is that it becomes easier over time and many even take pride in it. The reason why we need faith (believing in something we cannot verify), to understand God is because it is hard to think long term and also hard to wait.
Abstract concepts, like values and theology, are hard for many people to understand. That is why the Bible tells stories and why pastors go to seminary. One of the things that makes it harder to understand abstract ideas, than it is necessary, is because explanations are often too vague. All values should have specific situations that illustrate the situations, in which a certain value is personified. Art is a good way to illustrate abstract concepts.
If you study world history and religions, you will find that most societies and belief systems have very similar ethical rules. Many people think that there is no right or wrong in Chinese or Indian philosophies and religions, but the opposite is true. The ethics are not only the most important aspects of these belief systems, but Chinese philosophy is almost exclusively about ethics. In Hinduism and Islam, it is common to take additional rules, upon oneself, that aren't even required, by the religious doctrines, or even do rituals, that produce physical pain.
We often see God as requiring us to give everything we have to God, in exchange for eternal life and other things we cannot verify independently. God only ask us to acknowledge who He is and ask for His help and this is the entirety of the cost to us of salvation. Christ's cost for our salvation is the eternal suffering, on the cross, for our sins (because God experiences things outside of the limitations of time) The reality is, most of the Bible is about living in this world and finding joy in life. We are given freely from God, so it is natural for us to want to give freely to others.
Most people have trouble believing what God has said is true, because it is so different, from what we have been taught, in school. God wants us to be critical thinkers and, if you do not believe God, you need to speak to Him directly about it. You cannot start a relationship, without honesty, and God will take you from where you are. The secret to finding faith is prayer: if you can't believe, then ask God for faith. Reading the Bible and going to church helps increase your faith, as well.
Many people ask for proof, for them to believe in the Bible. First of all, no one has yet made a logical argument for logic and we believe things everyday that we cannot see or prove. Most people believe that the Earth is round and that we are a very small part of a very big universe and there are many very good proofs of this, but you are still taking someone else's word for something you have not experienced for yourself. Were there Weapons of Mass Destruction in Iraq before the US invaded and do businesses contribute more to society than they take?
The thing that makes people put a microscope on religion and politics is that the ideas are controversial. You can find proof, for any view of any political or religious ideas online and argue about it for years and never come to a conclusion. Some of these things have to be one way or another: something did or didn't happen and it happened at a definite time. Sometimes, in these debates, on some issues, we will never agree, because our emotions speak louder than our rational minds.
There is a God or there isn't and Christianity is either true of not. I believe. What do you think? Would you like to bet your eternity on it?
As far as historical proof goes, many people think that there never was an Israel and there is no conclusive archeological evidence, for some major events in the Bible. There is also little recorded outside the Bible about Israel, during the time of the Old Testament. There were many scholars, at that time, outside Israel. At the time of Christ, almost all of those people, from Ancient Egypt to Iraq were some of the earliest converts to Christianity. If these scholars didn't believe in the historical accuracy of the Bible, then why did they convert long before Christianity was legal in the Roman Empire?