I would like to know about the virtues of remembering Allaah and doing thikr (remembrance of Allaah) and how important that is.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger. 

There is much good in the perseverance in the remembrance of Allaah in this worldly life and a great reward in the Hereafter.

Among the benefits of the remembrance of Allaah and its importance for a person is that he feels assured and tranquil in his heart, and Allaah is with the servant and He mentions him with the angels (a more important assembly). In addition to this, Allaah has prepared a great reward for the person who remembers Him.

Allaah says (what means): {Those who have believed and whose hearts are assured by the remembrance of Allaah. Unquestionably, by the remembrance of Allaah hearts are assured.} [Quran 13:28]

Allaah also says (what means): {…and the men who remember Allaah often and the women who do so - for them Allaah has prepared forgiveness and a great reward.} [Quran 33:35]

Allaah further says (what means): {…and remember Allaah often that you may succeed.} [Quran 62:10]

Moreover, a hadeeth reads that the Prophet said, “The mufarridoon have gone far ahead.” They (the Companions) asked, “O Messenger of Allaah, who are the mufarridoon? He [the Prophet] said, “They are those males and females who remember Allaah much.” [Muslim]

The Prophet also said, “A human being has never done an action that is more likely to save him from the punishment of Allaah than the remembrance of Allaah.” [At-Tabaraani - Al-Albaani graded it hasan (good)]

Besides, the Prophet said, “Allaah, the Most High, says, 'I am as My Servant thinks of Me (expects of me); I am with him when he mentions Me. If he mentions Me to himself, I mention him to Myself; and if he mentions Me in a gathering, I mention him in a gathering that is much better than his (i.e. with the angels).'” [Muslim]

There are many other religious texts about the virtues of the remembrance of Allaah and its importance.

For more benefit, please refer to fataawa 12116and 84771.

Allaah knows best.