Assalaamu alaykum. I had missed three Friday prayers in a row in my old days, but now, praise be to Allaah, I do pray the Friday prayer. However, there is a hadith which says that Allaah will seal the heart (of one who misses three consecutive Friday prayers) and that he will not recieve guidance. I have read the answer of a brother to a similar question on this website. There, this hadith has been interpreted (otherwise), but the hadith clearly says that Allaah will put a seal (on that person's heart) and will not guide (him). So how can I convince myself that there is some hope left for the one who misses three Friday prayers in a row.?

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

As long as you have repented from this sin, then the repentant from a sin is like the one who has never committed a sin, as stated by the Prophet .

Since Allah forgives what is greater than that, which is associating partners with Him, and Allah may accept the repentance of a polytheist and enable him to remain steadfast on the truth if he sincerely repents to Him, then it is with greater reason that Allah accepts the repentance of someone who missed three Friday prayers in a row.

You should not despair of the mercy of Allah, as He is the Oft-Forgiving, the Most Merciful. Allah says (what means): {Say: O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.} [Quran 39: 53]

So, ignore these whispers from the devil; as long as you have repented and regret it, then your repentance is accepted, praise be to Allah.

Allah knows best.