There are three main schools of thought as far as Vedanta is concerned. These are:

1. Dualistic or Dvaita, 
2. Qualified Monism or vishistha Advaita, and 
3. Advaita Vedanta or Absolute monism.

All these Vedantic perceptions are true, and indicate one step higher level of Truth than the preceding one. All the three try to expound the relationship between, individual soul (Jiva), this world or nature (Jagat), and the Ruler of the universe or God (Jagdish).

Dualism, mainly propounded by Madhvacharya, maintains that the individual soul and the Supreme Soul are different and there cannot be unity between the two. The Ruler of this universe is creator, sustainer, and the destroyer of this universe. Nature and individual being can manifest and change, but He remains the same. Moreover, He is the repository of all good virtues. There cannot be anything defective or deficient in God. He is just all powerful, and merciful. We can get his blessings and thereby liberation or salvation from the cycle of birth and death by devotion, faith, and worship. Thus mostly, the path of dualism is path of Bhakti Yoga.

Qualified monism of Ramanujacharya, differs from dualistic thought on the ground that whatever we see or perceive is in fact God, and nothing else. The cause i. e. God has become the effect, i.e. this universe including all the nature and ourselves. ThusJiva, Jagat, and Jagdish are seen to be one and the same. Just as individual being has a body and a soul, so also this God has universe as the body and He is the soul of all souls. As from blazing fire fly millions of sparks, so also we are the parts of that Infinite Being.

Now comes the highest concept in the realm of spiritual philosophy as realized by Shankacharya, Advaita Vedanta. What is Advaita Vedanta then? How does it differ from qualified monism? Advaita Vedanta maintains that the Highest Reality or Existence or Truth cannot be two, but must be one. It has to be all pervading, only One, and Infinite. To think of its modifications into multifarious states is to degrade it to lower level of existence. If the Whole is divided into parts, how can the individual part be taken as the Whole. This is illogical by way of reason, and also on the basis of experience of the ancient Seers who realized the Truth as One and only One.

Advaita Vedanta maintains that there is only one Reality as Absolute Consciousness. Out of ignorance we perceive this One Reality as multifarious. This cosmic ignorance is called Maya.

In fact each soul is potentially That Reality. There is no God sitting in the heaven ready to punish the wicked or the sinners, or grant boons to the good. Evil and good are two sides of the same coin, just as death and life, sorrow and joy. It is all our ignorance that veils our vision about the divinity of our soul. We are, everyone of us, is son of that Immortal Bliss', not a sinner nor a saint! 

Relevance

To realize or experience this Truth is the aim of human birth. Scores of great souls have realized the Self in this manner, and of course, it is also our right too.

In this attempt to express the Divinity, values are born. One may not become a saint or a great souls, but even a little manifestation of the divinity is sufficient to make a person fearless and unselfish. The person becomes calm and collected, and love, compassion, and selfless service become his/her second nature. He begins to feel the same divinity in him in all others around him. He can't harm, hate, or be jealous of anybody. Depending upon the refinement of senses these wonderful qualities begin to manifest in his heart by degree. The barrier of 'selfish genes' is at last broken and the person becomes Free. His true nature as pure Consciousness begins to reflect in his personality, which is all love, bliss, and truth. True religion is said to begin with the attempt to manifest this value-system in our life.