We must get away from the Semitic concepts of Sin and Morality. Good and Bad, Right and Wrong.
Sikhi does not talk in terms of these concepts.
Sikhi talks about Hukam - the laws of nature
It talks about the 5 Thieves - Kaam Krodh Moh Lobh and Hankaar
It talks about being Just - and using Sabr, Santokh, etc to combat these 5 thieves.
Anyone is capble of being swayed by the 5 thieves (Mummooks), it is how much we tune in ourself into our Guru that counteracts this (Gurmookh).
I think Randipji has replied to that quite well !!
Sikhi explains our actions and temptations in line with the imposing thieves or weaknesses.
We have to get away from the concepts of- ''sin is wrong, you shall be punished for your sins...blah ..blah..''
This is not the way we should think or conduct ourselves, but of course sinning is wrong and we may feel like we are punished. But the idea is more of reaping what you sow, not of some God sat on a throne, watching us sin and then sending down some punishment.
The 'reap what you sow' or as Guru Nanak Dev ji says in Japji ''aapey beejh, appeyeh kahoa'
- Is more of a Universal concept, meaning that it can apply to us individually but it also applies to the acts of man messing with creation and nature. I strongly believe that world disasters or as insurance companies claim 'acts of God' are ALL due to mans actions on this planet.
With sin also comes the talk of forgiveness.
We should be more forgiving to others.
To ask or pray for forgiveness is not wrong in sikhism and I would encourage it. We can make mistakes without realising or ever knowing, so to ask for 'bhull chuk marf' is the way to ask in prayer for unknowing mistakes.
People ask or pray for all the joys and happiness in this world including most of us sikhs.
Personally. I prefer to not be asking for anything, but to just ask for forgiveness for any mistakes, wrongful doing to others, unintentional hurt or pain that I may have caused others..etc..- These are the things I mention in my ardaas rather than begging for the successes of this world.