Each Salah is expiation for the past sins

If the fortunate Islamic brother, who offers Salah regularly, commits sins (due to humanly weakness) between the gap of two Salahs, so the next Salah becomes expiation for the sins, that is, Allah عَزَّوَجَلَّ forgives the sins which are committed between both the Salahs.

Sayyiduna Haaris رَضِىَ اللهُ تَعَالٰی عَـنْهُ has narrated: Sayyiduna ‘Usman رَضِىَ اللهُ تَعَالٰی عَـنْهُ was sitting with us when a Muazzin came. Sayyiduna ‘Usman رَضِىَ اللهُ تَعَالٰی عَـنْهُ got some water and performed Wudu. He رَضِىَ اللهُ تَعَالٰی عَـنْهُ then said: I have seen the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم performing Wudu in the same way and I have heard  the Beloved Nabi صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم saying that ‘the person who performs Wudu the way I have performed this Wudu and then offers Zuhr Salah, Allah عَزَّوَجَلَّ forgives his sins, that is, the sins which were committed between the Fajr Salah and the Zuhr Salah; when he offers ‘Asr Salah then Allah عَزَّوَجَلَّ forgives his sins committed between the Zuhr Salah and the ‘Asr Salah; when he offers Maghrib Salah, then Allah عَزَّوَجَلَّ forgives his sins, committed between the ‘Asr Salah and Maghrib Salah; when he offers ‘Isha Salah, then Allah عَزَّوَجَلَّ forgives his sins, committed between the Maghrib Salah and the ‘Isha Salah, then he may spend the whole night lying and when he performs Wudu after getting up and offers Fajr Salah, so his sins, committed between the ‘Isha Salah and Fajr Salah, are forgiven and these are the virtuous deeds which keep the evils away. (Al-Ahadees-ul-Mukhtarah, vol. 1, pp. 450, Hadees 324)

Salah contains cure

The fortunate Islamic brothers who offer all five-time Salahs, by virtue of its blessing Allah عَزَّوَجَلَّ bestows cure upon them from diseases. Nowadays such new diseases are affecting people, the names of which have never been heard before. Despite spending hundreds of thousands of rupees these diseases are spreading. Acting upon the sayings of Allah عَزَّوَجَلَّ and His Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم if we offer Salah regularly, so اِنْ شَــآءَالـلّٰـه عَزَّوَجَلَّ we can attain salvation from the diseases. The Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم has said: ‘اِنَّ فِی الصَّلٰوۃِ شِفَاءً’ undoubtedly, Salah has cure.

(Sunan Ibn Majah, vol. 4, pp. 98, Hadees 3458)