Is the abundance of sins and returning to them after repentance, along with the presence of whispers of mockery towards prophets, considered hypocrisy? And is the servant's repentance accepted repeatedly, even if the sin is repeated and great, such as shirk (polytheism)?

No matter how great the sin, Allah's forgiveness is greater, and His mercy encompasses all things. Therefore, a Muslim should repent and not despair, and repeat repentance whenever the sin recurs. For Allah forgives what is sought in repentance, and one who repents from a sin is like one who has no sin.

Repentance is a sign of sound faith, not hypocrisy. One must not surrender to the whispers of Satan that beautify the abandonment of repentance. As for other whispers, the best cure for them is to ignore them and pay them no attention. They do no harm as long as the person dislikes them, and this dislike is a sign of sincere faith, for which the Muslim will be rewarded.