Status Of The One Who Dies Believing In Wilayah

Al-Majlisi I:

(In Al-Kafi) through a Saheeh (Authentic) chain from ibn Muskaan from Aboo Basir who said: I said to him (i.e. Imam Al-Sadiq (a.s)), "May I be sacrificed for you, do you see the one who rejects this matter (Al-Wilayah) to me as if he has rejected you?" He (a.s) said: "O Aboo Muhammad! The one who rejects this matter to you, so he has rejected against Rasool Allah (saw), and against Allah (swt) Blessed and High. O Aboo Muhammad! The dead ones from among you who were upon this matter (Al-Wilayah) is the martyr." I said, "Even if he died upon his bed?" He (a.s) said: "Yes, by Allah (swt), even if he died upon his bed, he is alive in the presence of his Lord being given Sustenance."

Also through a Saheeh (Authentic) chain from ibn Muskaan from Malik Al-Juhany who said: 

Aboo Abdullah (a.s) said to me: "O Malik! Will you not be happy that you establish the Prayer, and you give the Zakaat, and you restrain yourself, and you enter Paradise? O Malik! There is none from the people who followed an Imam in this world except that he (their Imam) will come on the Day of Judgement cursing them and they would be cursing him except for you and the one who is similar to your condition. O Malik! By Allah (swt), the dead ones from among you who were upon this matter (Al-Wilayah) is a martyr of the status of the striker with his sword in the Way of Allah (swt)."

Source: Rawdhatul Muttaqeen. Vol. 13, Pg. # 215.