[Allah says in the Qur`an - interpretation of the meaning] "See you not how Allah sets forth a parable? - A goodly word as a goodly tree, whose root is firmly fixed, and its branches (reach) to the sky (i.e. very high). Giving its fruit at all times, by the Leave of its Lord and Allah sets forth parables for mankind in order that they may remember" [14:24-25].
This tree is a parable of life itself. Just as the tree is the building block of life, iman is the building block of spiritual life. The roots are firm. This shows that it is strong and powerful. It cannot be moved or shaken. In the same way, iman must be firm in a person`s heart. A person must have a firm foundation and stability with the roots of tawheed.
The branches reach up to Allah and towards jannah. They cover up everything else and cannot be covered. In the same way, iman cannot be covered up. Nothing can conceal this tree that reaches all the way to the sky. This means when you have iman, you will see it manifested in your actions. A tree like this is a landmark that people look to, take direction from, and take inspiration from. A person with iman becomes the anchor of the community, and people will look to him for an example.
The tree of iman gives you comfort like shade and fruit. There is no tree on the face of this earth that is fruitful at all times, except the tree of iman. It can nourish you at any time or place. Only the tree of iman gives different types of fruits. The fruits also replenish themselves all year, in the same way that iman needs to be constantly replenished.
This parable shows us the importance of having the correct theology of our beliefs. When we establish that firm root, we bear the fruit. It is the parable of La Ilaha illallah: the Goodly Word. Whoever plants la ilaha illallah in his heart and nurtures it, the fruits it will bear him are no less than entrance into Gardens as vast as the Heavens and the Earth. The roots of iman are so deep, that once true faith enters one`s heart it will remain there forever.
Heraclius said to Abu Sufyan in the famous hadith from Sahih al-Bukhari, "I asked you whether his followers were increasing or decreasing. You replied that they were increasing, and in fact this is the way of true faith, till it is complete in all respects. I further asked you whether there was anybody, who, after embracing his religion, became displeased and discarded his religion. Your reply was in the negative, and in fact this is (the sign of) true faith, when its delight enters the hearts and mixes with them completely".(Saheefah)