"I hope this doesn't feel like we're grilling you and trying to knock your faith or whatever. Not trying to, just giving my side."
Not at all! It's nice to have a pleasant conversation on these matters
Sharky and inthesky: Why the bible, why believe in Christ.
Well, pretty much most historians will point out that Jesus was an actual person, regardless if you believe his miracles or not. In fact, there's "more chance" of Jesus existing than Socrates, and the second one is almost irrefutable.
Now, why believe he is the son of god? Well, for the same reason israelites thought so back in the first century: the prophecies. Many of the things that happened to Jesus were predicted several hundreds of years before.
Which leads to "why the bible". The bible's predictions weren't just about Jesus. For example, the book of Daniel predicts the progression of empires that would rule the "biblical" lands. Empires were predicted to fall centuries before they even rose.
Only someone a step above human intelligence could predict such things.
As for
"why this potential intelligent designer would give us these rule books and guides that all seem really outdated in our current society"
Because most of the rules (almost every one of the old testament) were for the Israelites before Christ, they do not apply for christians. Jesus abolished the Law, and laid down the groundwork for a righteous worship of god that could include anyone, regardless of nation (as opposed to before where the Israelites were god's only supported nation).
"identity theft or off shore tax havens!"
Pslam 26:4 ; Romans 13:7 be creative :p
But seriously, as you said before, the bible has excellent advice and guidance even for today. Otherwise it wouldn't have lasted such a long ass time. And with careful examination, you'll come to the conclusion that the bible has very little rules to be applied today, rather gives guidelines to have a joyful life, regardless of the century we're on.
Of course I would say my religion is the right one. But rather I'll just give this food for thought:
There are only 2 religions: the right one and the wrong one. If the right one follows the bible, then you just have to hear what the bible has to say.
(I do hope I'm not sounding preachy. Totally not my objective..)