What is the ruling on one who had blasphemous thoughts, acknowledged them, and was at ease with them for a short period, then rejected them and regretted them, and is he considered a disbeliever?

Whoever settles disbelief in their heart and is content with it, disbelieves; for Allah Almighty says: "But whoever opens their breast to disbelief, on them is wrath from Allah, and for them is a great torment." This question is a continuation of whispers and doubt regarding disbelief. So, the questioner should distance themselves from these whispers. Whoever entered Islam with certainty does not leave it except with certainty, and not merely by fleeting thoughts of disbelief that the heart dislikes and is not content with.