The question is "Why (or why not) be Christian" - well, I can only speak of my own experience. I was brought up a Christian, and I continued as a practising Christian into my 30's and early 40's. In fact, I had quite a dramatic experience when I was 20, when I became ill and I cried out to God in fear and desperation, and (after several months) events fell into place and I experienced a very dramatic turnaround which I think of as God stepping in and healing me. (Although I admit, as others have said earlier in this thread, that what I experienced could, theoretically, be thought of as 'coincidence', or 'mind over matter' - there is no way to scientifically PROVE that it was God, but let's just say it was good enough for ME to start believing in Christ). Anyway, even though I had this dramatic 'stuff' happen to me, of course life is never that simple. I always dreamt of getting married and having a family, but as much as I tried, it just never happened and I gradually became very bitter and angry with God, for dealing me this hand of cards. From approx 2005 or so, I sort of gradually stepped away from faith and from the church, and I became very angry with God for leaving me single and alone (although I never actually stopped believing in Him, I just was in a very bad mood with Him). I was so angry, but deep inside I knew I was acting wrong and that this attitude was getting me nowhere and just making me more and more unhappy as the months/years went by.
I remember it was just before lockdown started, about this time 4 years ago, I got to the point of no return (so to speak) and I got on my knees and tearfully prayed "God, you win, you are right and I have been wrong. I will accept being single if that's what you want for me. Please forgive me my awful, hateful attitude towards you and allow me a fresh start and I'll try to live my life your way" (or words to that effect).
Up until that point, the worst thing about my life was that I felt like I was just drifting aimlessly in a void, or a thick fog. There was no sense of journey, time seemed to be just wasting away. But since then, it's as if God has lifted me up and placed me on a sort of conveyor belt which is moving slowly towards Him. Step by step, little by little, I feel as if I'm now on a purposeful journey in the right direction. And because of my time away from faith, I realise how important it is to keep hanging in there, even when it doesn't FEEL right. For example, right now it seems like my health is deteriorating. I'm losing my hearing (in fact I might start a thread on that, as I want to see if anyone else has the same symptoms), I'm having IBS-type symptoms, etc etc. And I'm thinking back to when I was 20 and I experienced an 'intervention' (some might say a 'healing' in answer to prayer) and yet now, after much praying I don't YET seem to be experiencing any answer or turn-around in my situation. So let's not lie or paint a false picture: prayers don't always get answered, at least not immediately, and it leaves me questioning whether this whole experience is 'real' or merely 'in my mind'. Yet somehow this time, I'm choosing to hold on to faith in Christ, as I've seen what it's like when I choose to disregard him and turn away.
So to sum it up, being a Christian is not always easy, and life still throws stuff at you and you have to hang on, and there are times when you think God, Where are youuuu!!! Why are you not answering me? Aaargh!! Is this all a delusion? Am I kidding myself? But I think I have enough internal evidence to convince me that faith is a positive and true choice.