I got the following from the book 'Pearls of Wisdom 2', Compiled by Mufti Saiful Islam, Bradford. Take a read:
Harmful Effects of Sinning
Every sin produces the following outcomes:
1. Allah's (Subhanahu Wa Ta'aala) anger and displeasure.
2. Shaytaan's triumph and delight.
3. Moving further away from Jannah.
4. Approaching Jahannam.
5. Harming one's own soul and self.
6. Stains appear and cover the heart with black spots.
7. Pain and causing harm to the angels who accompany the individual.
8. Rasulullah (Sallallahu Alayhi Wasallam) becomes grieved (because the Ummah's actions presented to him regularly).
9. The ground upon which the sin had been committed will testify against the sinner.
10. It causes great harm to the creation because through sins, Allah's (Subhanahu Wa Ta'aala) Mercy is reduced due to which even the lifeless creatures are badly affected.
[From: 'Pearls of Wisdom 2', Compiled by Mufti Saiful Islam. Online Web Address: http://www.al-mumin.org]
Wassalamu Alaikum Warahmatullahi Wabarakatuh.