"Pardon me but I think you suffer from the mistaken perspective that your practice and only your practice is correct. This quote from your text expresses it well:
"a large number of mistaken and different sects"
Answer: First of all, Religions are founded by and came from a religious founder, of course. Like in Buddhism, Shakyamuni Buddha, Christianity is Jesus Christ and etc. If we take a look in ourselves of what are their fundamental or basic teachings that they have taught and what are their true spirit that they conveyed to us. If we don't know or follow the exact spirit from these great leaders then we are swayed to the true path. If that is the case,then, we suffered from it or what u had said we are yeilding into the evil Omen or in Buddhism we go into down to the evil paths ,instead, we are going to the state of Buddhahood or the state of absolute happiness(the highest of 10 life condition) in which shakyamuni had taught to it, we go into four Lower worlds(hell, hunger, animality , anger...etc) and these are lower state of life condition that brings us to sufferings.
In the case of Buddhism, they are very complex forms and they differ from one another.Of course, they are practicing Buddhism because they came from Buddha's teachings. But the question is, are they following the correct path of the true spirit of Buddhism from the spirit's founder Shakyamuni Buddha? Your decision or your wisdom can tell u that. Another also, they are practicing but partial truth about Life because they based on their teachings on the provisional both hinayana or mahayana teachings. When we say provisional it is mistaken or inferior teachings. I want to say on you, that the LOTUS SUTRA(the true Mahayana ) itself is the true teachings of Buddha and his only true DHARMA(law, truth, justice...). It is the king of all sutras. It is regarded as the most definitive tachings of Shakyamuni for the last 8 years of his life and the only sutra that brings poeple to the path of Buddhahood. Buddhism can clearly see the difference of their truth whether it is impartial or partial, inferior or which on it is superior.
I think that should be the kind of spirit or principles of what other religions have in which one is inferior and which one is superior?