Assalaamu alaykum. With regard to every good act and/or act of worship, I notice that there are levels, one higher than the other. For example, while there is a reward for saying, 'Assalaamu alaykum', there is a greater reward in adding, 'wa rahmatullaah', and even a greater reward in adding, 'wa barakaatuhu', to it. The same goes for praying, wearing the hijab, and so on. I notice that there are levels beyond the basic ones that are more rewarding the more we strive and make effort. As of now, I am a person who is sticking to the basics but who tries to learn and change wherever I can and aspire to higher levels in all aspects of worship and good deeds. My question is: can I take my own time and change as per my level of comfort (provided that I am doing the basics), or is it sinful for me to not try to attain the highest levels of worship and reward all at once? Kindly clarify.

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, sallallaahu ʻalayhi wa sallam, is His slave and Messenger. 

There is no doubt that the Muslim should keenly seek to earn greater rewards; however, the person does not bear a sin for not performing voluntary acts of worship, nor is he obliged to perform them all at once or even gradually. The Muslim is not Islamically obliged to perform the voluntary acts of worship as long as he observes the obligatory acts of worship.

Talhah ibn ʻUbaydillaah reported:

“A man came to the Messenger of Allaah, sallallaahu ʻalayhi wa sallam, asking about Islam. He, sallallaahu ʻalayhi wa sallam, said, '(You are obliged to perform) five daily prayers during the day and the night.' The man asked, 'Am I obliged to perform any other prayers besides these?' He, sallallaahu ʻalayhi wa sallam, replied, 'No, unless you perform more voluntarily.' The Prophet, sallallaahu ʻalayhi wa sallam, then informed him of the obligatory fasting in Ramadan. The man asked, 'Am I obliged to fast anything else besides this month?' He, sallallaahu ʻalayhi wa sallam, said, 'No, unless you do more voluntarily.' The Prophet, sallallaahu ʻalayhi wa sallam, then informed him of the obligatory zakah. The man asked, 'Am I obliged to pay anything else besides this?' The Prophet, sallallaahu ʻalayhi wa sallam, said, 'No, unless you pay more voluntarily.' The man turned back, saying, 'By Allaah, I will neither make any addition to this nor decrease anything from it.' The Messenger of Allaah, sallallaahu ʻalayhi wa sallam, said, 'He will succeed if he is sincere (i.e. if he is saying the truth, he will succeed).'” [Abu Daawood]

This man stated that he would observe only the obligatory acts of worship and not perform voluntary acts of worship, and the Prophet, sallallaahu ʻalayhi wa sallam, did not say that he would bear a sin for that. On the contrary, he, sallallaahu ʻalayhi wa sallam, remarked that he would be successful if he was truthful and observed the obligatory acts of worship.

However, the Muslim should keenly strive to perform more good deeds and observe voluntary acts of worship to the best of his ability, even if gradually, because this is one of the means of earning the pleasure of Allaah and making one's balance of good deeds heavy on the Day of Judgment as well as amending any deficiencies in one's obligatory acts of worship.

Allaah knows best.