According to Chapter 20 of the Quran, Paradise is for one who purifies his soul in this present world and reaches the world Hereafter with a purified personality. (20:76) This reality has been clearly described in many verses of the Quran. Attainment of Paradise will be based on individual merit rather than on personal affiliation to any community or group.

Paradise, therefore, is only for the individual who purifies himself. Purification means abandoning a life of unawareness and leading a life ruled by the conscience. A person has to save himself from anything which comes in the path of truth, and when he faces any hurdles, he must not resort to expediency. When desires arise within him, he must crush them, and when he is overtaken by arrogance, he should be able to overcome his overweening pride.

Tazkiya means purifying the individual of unfavourable elements, so that he may reach the point of perfection in a favourable environment. This was a very important task given to the prophets.

A prophet makes the greatest possible efforts to prepare human beings whose hearts are free from the love of all else except the love of God. He strives to bring into existence such souls as are free from complexes and are worthy of receiving the divine provision from the universe.

Purification is the principal condition for entry into Paradise. Without purification, one can never gain entry into the eternal heavenly abode.

Source: Discovering God