Seers have called them by different names. We say 'sin' in Christianity, but actually it is not the hell-fire and brimstone stuff; but simply a transgression of the Law; that which binds us. We call this Ignorance in Yoga Philosophy or an impediment or obstacle standing in the way of Truth.
In Yoga Philosophy, if you do not exist, then nothing else does, so as long as you exist, then logically you are the greatest problem and also the answer to solving the problem. It is seen as inherent. Not outside you, but within.
We say: "He did this to me. She did this to me." But in reality, we are ourselves the dirty mirror as well as the gold nugget. What needs removing is the fear, greed, hatred, ego, malice, attachments; desires, insecurities ... a long list.
Man is both frail and weak. Hence the necessity for spiritual practice: prayer, meditation, devotionals. All scriptures recommend this. So what is our greatest enemy? Ignorance. If we truly knew who Christ was, then we would not have killed Him. If we knew that there was Something better than grabbing and pulling , then we would not pursue them. Much Love.