A happy life

Happiness is the universal goal of people in life – whether they are philosophers of a high intellectual caliber or unlettered laborers -- everyone strives in search of happiness and looks for ways to escape the worries of life.
However, most people achieve only partial or superficial happiness, which provides temporary relief from their problems. In order to search for everlasting happiness that leads a person to true success, one must keep an open heart and mind, as the wise one is he who searches for the truth and adopts it immediately.
1. The most important means of happiness and the foundation of all felicity are to have sound belief and perform righteous deeds.
The Almighty God Says: [Whoever does righteousness, whether male or female, while he is a believer - We will surely cause him to live a good life, and We will surely give them their reward [in the Hereafter] according to the best of what they used to do.] (The Holy Quran 16:97)
The Almighty God promises whoever possesses sound belief and performs righteous deeds then will have a happy life and will also be rewarded in the eternal Hereafter.
The reason for this is obvious: those who have the correct belief which leads to righteous deeds, reformed hearts and refined manners have the basic foundation that they can refer to in any event – regardless of whether these are matters which cause joy and happiness or sorrow and dejection.
The Prophet (PBUH) described this quality of the true believers when he said: “How wonderful is the affair of the believer! All of his affairs are good and this is the case for nobody except a believer. If he is blessed with prosperity he thanks (Allah) and that is good for him; and if he is afflicted with adversity he perseveres and that is also good for him.”
The Prophet (PBUH) informed us that a believer's reward would be multiplied many times over, regardless of whether what befalls him brings him joy or sorrow.
2. Keep yourself busy in performing beneficial deeds and acquiring useful knowledge.
By doing so, your heart will be diverted from whatever causes it grief and sorrow, to the extent that a person may completely forget his worries and unhappiness and become happy and energized. This is something that is common to believers and others, but the believer is distinct due to his belief, sincerity, and his hope for reward while learning or performing beneficial deeds. If this deed is an act of worship then he will receive the reward for it, and if it is a worldly task which is accompanied with a good intention, such as working for the sake of being able to worship The Almighty God better. Then this will have a strong effect in removing his anxiety and grief.
3. Concentrating on the tasks at hand, not being anxious about the future and not crying over the past is another way of attaining happiness.
This is why the Prophet (PBUH) sought refuge with God The Almighty from anxiety and sorrow. Usually, a person experiences sorrow due to what has passed and cannot be retrieved, whereas grief is due to anxiety for the future and the fear of what may happen.
A believing slave of The Almighty God should live for the current moment, focus, and exert the utmost effort to utilize his time in the best possible way. This will enable him to accomplish his tasks and forget his sorrow and grief. When the Prophet (PBUH) made a particular supplication or guided his nation to do so, he would also encourage them to exert efforts to obtain what they supplicated for and shun everything which might prevent the prayer from being answered.
As the Prophet (PBUH) said: “Be keen to do that which will benefit you, rely on Allah, and do not be lazy (by not exerting effort) and say when a problem befalls you: ‘If only I would have done such and such, then the result would have been such and such’ rather, one should say: ‘This was decreed by Allaah and He does what He wills.’ Saying ‘If’ opens the gate for Satan (to cause discontent).”