If the Bible is true then God exists.
If Baha’u’llah was a Messenger of God then God exists.
Similarly, if the premise Baha’u’llah was a Messenger of God is true, then the conclusion God exists must be true.
None of these are circular fallacies, they are all valid statements
A circular fallacy is when you use an unjustified conclusion to justify itself so to speak.
A simple example could be (Assuming we knew nothing about rabbits):
Rabbits can't be green, because green rabbits don't exist.
If you split them into two statements:
A. Rabbits can't be green
B. Because green rabbits don't exist.
So if I asked you, how do you know that rabbits can't be green (A)? Your answer would be drawing on your unjustified conclusion of B, which is that they don't exist.
Equally, if I asked you, how do you know green rabbits don't exist? You use the unjustified conclusion of A to justify B.
We all suffer from circular fallacies, it is not a unique thing. But we can use knowledge to at least reduce it. In the example above, we do have a lot of knowledge about rabbits to draw on and based on this we can with high confidence say that green rabbits don't exist. Even though it might be wrong, we have so much evidence that this simply doesn't happen naturally that it is not just grabbed from thin air.
So in your example:
If the Bible is true then God exists.
This statement is true because it doesn't rely on God to be true for the bible to be. Because you use the condition "If the bible is true" then "God must be". So everything relies on whether or not the bible is true.
This wouldn't work the other way around, if God exists the bible must be true. That is a fallacy as well because there are lots of God(s) and even if God exists the bible could contain errors in the form of human mistakes.
Yes, there are teachings and laws in religious scriptures, telling us what we should and should not do, but I don't see that as manipulation. If parents tell their children what they should and should not do is that manipulation?
Well it is manipulation, it's not necessarily bad. Even lying to children is not always harmful even though it is also manipulation. For instance, telling them that Santa is real can make them excited and happy etc, which is good. Lying to them to prevent them from doing something that could potentially harm them would also be good.
But the laws in the Bible rely on whether God said this or not, and even then a lot of them are very questionable from a moral point of view I would say. To the point where one could wonder if an all-mighty God really cares about such things and might not have better things to do?
No, religious leaders should not be telling people what to do since they have no authority to do so. They are mere humans.
Believers might go to them for guidance but it is better if believers go to the texts themselves and so as they say.
Yet they do, I have never heard of any priest or spiritual leader of any kind present any evidence of their authority to do this or even give a reasonable explanation of why anyone ought to do what they are saying? They go to school and get a degree and then they have "authority", that doesn't really seem like how God intended it to work.
It is not only the religious leaded who don't follow the rules, but rather bend and twist them to fit with the modern world. It is also the religions believers. For example, fornication is prohibited in the Bible, but most Christians have sex out of wedlock.
Agree, everyone does it. And then they explain it away with people being born sinners and what other nonsense. You just have to listen to the banana man (can't remember his name Ray Confort or something I think?) and the tactic he is using is extremely obvious, bogus and completely unjustified.