How do we reconcile the texts that indicate the acceptance of a penitent's repentance, even if he repeatedly returns to sin, with the texts that forbid returning to sin and consider it a sign of disrespect towards God, taking into account that a servant may fall into sin after sincere repentance?

Allah forgives all sins if the sinner repents with sincere repentance. One must renew their repentance whenever they return to sin and not surrender to Satan. Allah the Almighty said: ﴿And those who, when they commit an indecency or wrong themselves, remember Allah and ask forgiveness for their sins — and who forgives sins except Allah? — and do not persist in what they have done while they know.﴾ [Surat Aal ‘Imran: 135]. It is narrated in the Sahihayn: “A servant committed a sin and said: ‘My Lord, I have committed a sin, so forgive me.’ His Lord said: ‘My servant knows that he has a Lord who forgives sins and takes to account for them. I have forgiven My servant.’ Then he committed another sin and said: ‘My Lord, I have committed another sin, so forgive it for me.’ His Lord said: ‘My servant knows that he has a Lord who forgives sins and takes to account for them. I have forgiven My servant; let him do what he wishes.’”