Following are a number of back-translations as well as a sample translation for translators of Proverbs 28:13:

• Kupsabiny: “A person who hides his sin/evil does not prosper/progress,
  but the one who admits (the sins) and renounces (them), God has mercy on (him).” (Source: Kupsabiny Back Translation)
• Newari: “If [you] do not repent of your sins
  you will never be able to prosper.
  If you repent and turn from your sin
  God will have mercy on you.” (Source: Newari Back Translation)
• Hiligaynon: “You (sing.) will- never -prosper if you (sing.) will- not -confess your (sing.) sins, but if you (sing.) confess them and turn-away (from it), God will-have-mercy-on you (sing.).” (Source: Hiligaynon Back Translation)
• Kankanaey: “The life of those who conceal their sin is not good, but God shows-kindness/mercy to those who confess and turn-their-backs-on their sin.” (Source: Kankanaey Back Translation)
• English: “Those who refuse to confess/admit their sins will not prosper,
  but God acts mercifully/kindly toward those who confess their sins and turn away from their sinful behavior.” (Source: Translation for Translators)