Do the levels of worshipping Allah vary, such as the worship of love, the worship of seeking reward, and the worship of fear? And does their reward differ? And if so, what is the highest level of worshipping Allah, and what is the way to achieve it?

Slavery (servitude to Allah) has ranks mentioned by scholars, and Ibn al-Qayyim enumerated fifteen of them, which can be referred to in the book "Madarij al-Salikin" (Ranks of the Seekers). As for the examples mentioned by the questioner, such as love, fear, and hope, these are fundamental acts of worship that a Muslim must combine in their worship of Allah. They should worship Him out of love for Him, fear of His punishment, and yearning for His reward. The Holy Qur'an mentions verses of encouragement and warning, commands fear and hope, and urges love, such as His saying, "And invoke Him with fear and hope," and His saying, "Indeed, they used to hasten to good deeds and supplicate Us with hope and fear, and they were to Us humbly submissive," and His saying, "Allah will bring forth [in place of them] a people He will love and who will love Him," and "But those who believe are stronger in love for Allah."