Hinduism is a complete religion with no loose ends and all questions have answers within its concept. There is no denying. There are other beliefs that have huge gaps and are explained away by simply saying that God is impossible to understand fully. If anything God is indeed very easy to understand by simply loving Him, the rest just follows. A cult is something that a person starts, attracts people to it with rewards, even kills fellow humans to convert, has hard and fast rules, if not followed, permanent punishment like eternity in hell etc are advocated to keep the followers in the flock.
Any diversion is scorned.
All free thinking is banished. The flock is ordered not to discuss other faiths. Even the love and respect of your land's rivers, mountains and Holy places suddenly become simple water and dust and at the same time be replaced by Mecca or some city in the Middle east. Non believers are called names in derogatory terms to keep the flock under the cult leader. Animals are sacrificed in the name of God, but for the selfish purpose of consumption and self gratification.