I am a Christian. I'm not a very good Christian, but I do my best.
Jesus was very clear. The first, most important thing was to love God. The next was to love others. Everything else flowed from that. If you followed those two then you couldn't go far wrong. God made it simple for us. Start with love.
Man, on the other hand, made things complicated. Jesus had a few choice words to say to the Pharisees who were so wrapped up with rules. The rules were not important, the love was.
Stepping away from the theology (which I am nervous about) to history (much more confident), the history of monasticism in Europe in the Middle Ages is fascinating, and tells us a lot about human beings. The most common basic rule was that of St Benedict. There were others, but in the lead up to the Reformation most monasteries had a variation on the Rule of St Benedict. You can find an explanation of the Rule in Wiki here and a copy of the rule here. I suspect it is very human to use rules as a sort of comfort blanket. The rules about food spread out from the monasteries into society in general. They got very complicated.
The rule was that every Wednesday, Friday and Saturday you should avoid meat. That's not a bad plan in today's western society for the benefit of the planet and our health. Then there were rules about what counted as meat. Eggs and milk were forbidden, which isn't so good in a northern, medieval society. Fish was fine, you could fill up with fish - if you could afford it and there were lots of rules which meant that most people couldn't go off and just catch it as the local lord had all the fishing rights. You couldn't fry in animal fats, you had to use expensive olive oil that in England had to be imported. Lent was a forty day stretch where it was only vegetables and fish. The fasts stretched out. All of Advent was a fast so in December when a warming bacon stew would be welcome it was strictly fish or veggies. It made little difference to the very poorest, but it must have been a strain on a housewife who had the money to make choices about food. You really had to meal plan.
Of course, as soon as a rule about fasting was made, wonderful human ingenuity found the loopholes. You couldn't eat beavers during a fast, but you could eat their tail, as their tail was technically fish. For some reason so were baby rabbits. Whalemeat, dolphin and porpoise were enjoyed as very meaty fish. Cooks in the great hall made huge efforts to sidestep the rules. There were recipes to make fake boiled eggs using rice and expensive spices. Cow's milk was substituted with almond milk, made with expensive imported almonds and with a great deal of effort. The faith part of fasting - having less to focus on God - was rapidly overgrown with religion and its rules. I can only imagine the bafflement of the angels.
I like the rules. I know it isn't helpful, and rules are not faith. However today I won't eat meat. It's not a big thing, I'll have tinned tomato soup for lunch and fish fingers for dinner. It used to be the fast before the day of Christ's birth. I'm not sure whether I am avoiding meat because of my faith or because I love history. However making a conscious choice over food so that I am prompted to remember God isn't a bad thing, at least for me.
Now I am going to go off and remember that's it about the love.