As-salaamu 'alaykum, my question is about the obligation of Hajj. Since it is one of the five pillars, does that mean one who has not done it in this dunya has commited a major sin? Such as if a person had the means at a certain time but did no go when he could have, but then later on he regrets not having gone but no longer has the means, and he doesn't get another opportunity until he leaves this dunya. So could he still be forgiven by repentance or by some other good deeds for his lack of accomplishing the Hajj? Also, it is known in a Hadeeth that stuggling in the path of Allah is more virtuous than Hajj. But even with that, would such an person still be lacking in his deen because he didn't accomplish a pillar (Hajj)?

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 ‘alayhi wa sallam, is His Slave and Messenger.

The preponderant opinion, as discussed by the scholars, is that Hajj is an immediate obligation. Whoever is able to perform Hajj must do so right away. For more benefit, please refer to Fataawa 91223 and 87129. So, if one delayed Hajj while he was able to do it, then he is sinful. As long as he remains able, he must take the initiative to perform it and seek repentance for any delay.

If he becomes no longer capable to perform Hajj, then he must sincerely repent for delaying it and he must be determined to fulfill it as soon as he becomes able to perform it. If his repentance was truthful, Allaah will forgive him his sin and it will be as if he never committed this sin. It was reported from the Prophet, sallallaahu ‘alayhi wa sallam, that he said: “The repentant from a sin is like the one who has no sin.” [Ibn Maajah - Al-Albaani graded it Hasan (good)]

If this person dies and his estate contains enough money to cover the Hajj expenses, then that amount must be taken out of the inheritance [and Hajj must be performed on his behalf], since in this case the dead is still liable for the debt of Hajj, and the debt of Allaah has the most right to be settled. If his estate does not have this amount, then there is no obligation upon the heirs.

Allaah Knows best.