Honestly, I wish I could give you a simple answer, but I can't. We are now leaving the clear-cut black and white and entering the grey area. There are varied answers to your questions, it depends on who you ask. I can only give you an answer based on my own understanding and interpretation of Gurbani and the teachings of the Gurus, there are other Sikhs who feel differently, and they are free to chime in whenever they want and answer from their own perspective, but the following answer is my own, I do not claim to be speaking for every Sikh in the world.
I think what you are getting is that, for followers of religions with personified/personal deities, they pray to their God(s) during hardships, and they believe God will help them. They do what their God has told them to do in hope of getting some sort of reward (i.e. salvation) in the afterlife, but since Waheguru does not intervene a la miracles/wish granting, and there is no reward for anything in the afterlife, what is Waheguru good for? Why believe in God to begin with?
In the past, when I was Muslim, the only being I was concerned with pleasing was Allah. Muslims are taught to do things "for the sake of Allah". Do not use drugs/alcohol "for the sake of Allah", be kind to your fellow Muslims "for the sake of Allah", basically, the best way to do something is to do it "for the sake of Allah". And in the end, you are promised some sort of a reward (from Allah) for your submission. Everything that happens is the will of Allah, if something good happens, thank Allah, if something bad is happening, it is Allah testing you, and you should stick it out, make dua and move on.
Accounting myself responsible for my own life has helped me a lot. I do not pray for material/worldly things anymore. Instead, I ask myself every night before I go to sleep to stay true to myself, to remember that God is within me and that all I have to do is look in my heart. Sikhi liberates me from having to look outside of myself for happiness. It has bestowed upon me the realization that I am powerful enough to make all my dreams come true ON MY OWN, that I can ground the world to my vision, that I am capable of creating my own little corner of heaven on this planet while I am still alive, I do not have to wait until I die. Before, life was a prison, as a Muslim, I worked everyday for death, I was waiting to die so I could get my reward. Now, I love life, this life, the only life I will ever have as the person who is typing this up, if I want something, I must go after it NOW, my ultimate goal is to leave the world a better place than it was when I was born.
What does God do? Waheguru, to me, is like an infinite power-source that I am able to tap into whenever I wish. I can do this through meditation, I can do this through recognizing the light of God in all of creation and I can do this by living my life truthfully. Guru Nanak, the first Sikh Guru, said "truth is high; higher still, is truthful living." When addressing Muslims, he said "Let mercy be your mosque, faith your prayer-mat, and honest living your Koran. Make modesty your circumcision, and good conduct your fast. In this way, you shall be a true Muslim. Let good conduct be your Kaabaa, Truth your spiritual guide, and the karma of good deeds your prayer and chant. Let your rosary be that which is pleasing to His Will. O Nanak, God shall preserve your honor."
I do not feel like I need fasts, pilgrimages, prayer mats etc... to realize God. I do not need to pray a certain number of times a day, nor do I need to go to Mosque, or prostrate myself towards the Kaabaa. All I need is to be merciful, live honestly, be modest, have good conduct, protect truth and perform good deeds to realize God.
If I ever pray now, it is to remember that I have the strength to move forward from any situation. I no longer rely on the genie in the sky to get me out of tough situations, I ACT, I hold myself accountable for things that are in my control and work hard to make the best of any situation, I would rather spend my time tackling the issues head on than begging God to do it for me.
I have a plan of my life, the long-term goals, what I want to accomplish, and I remember that any hardships are stagnant, they are not reality, it is only temporary. I remember that my Waheguru gave me a heart, a brain, and most importantly, family and friends I can lean on for support in any situation. And with those things on my side, I know I can overcome any hurdle.
"Oh dear God, please, I beg you, please help me get 90% on my next exam, please stop my boss from being such a dick, please make me get into medical school, and if you do, I will pray 'x' number of times/donate 'x' amount of money money/spend 'x' number of days fasting" etc...
Childlike faith might be cute in children, but it is downright silly in adults. Like praying to Santa Claus. I cannot bargain with God, for the simple reason that I have nothing to bargain with, everything I have already belongs to God, I have nothing to offer. Sikhi has given me a belief system that, quite simply, treats me like an adult. There is no "pie in the sky", I am accountable for my own actions, it does not guarantee me an easy life, it guarantees that life will be hard, life's middle name is "problem". HOWEVER, it gives me a pathway that will carry me through any problems in life, but walking that pathway is up to me, I must be strong enough to put one foot in front of the other and keep moving forward no matter what life throws my way.
I look to the Gurus for inspiration. I read about their lives and it makes me think, if they can go through all of that, be burned alive, have their loved ones killed in front of them, go days without food, have their entire world burn around them, and still, even after all that, they kept moving forward and stayed in Chardi Kala (high/optimistic spirits), then what excuse do I have?
By seeing God in all, I am able to find little gems of inspiration in the struggles and triumphs of those around me. God exists in all, and through them, there are gems of inspiration to uplift me when I need motivation. And once I am out of my own troubles, perhaps the hurdle I jumped over will be of inspiration to someone else.
The Gurus were perhaps the first teachers of "nothing is impossible, impossible splits up into 'I-M-Possible!'". Sikhi teaches self-dependence, self-reliance, faith in yourself, if things are falling apart, there must be something wrong with the concept of the project at hand, I go back and reevaluate what I am doing, figure out what was wrong and move on.
We have to learn to grow. Miracles are no good, who gets helped when prayers are answered, what do you learn? Sikhi is an education, a way of life, the moment we lose sight of that, we fall back onto the Abrahamic/Vedic ways of doing things, the very trap Guru Nanak was trying to save us from.
This is how I view God in Sikhi:
Gauree Gwaarayree, Fifth Mehl:You are my Companion; You are my Best Friend.
You are my Beloved; I am in love with You.You are my honor; You are my decoration.Without You, I cannot survive, even for an instant. ||1||You are my Intimate Beloved, You are my breath of life.You are my Lord and Master; You are my Leader. ||1||Pause||As You keep me, so do I survive.Whatever You say, that is what I do.Wherever I look, there I see You dwelling.O my Fearless Lord, with my tongue, I chant Your Name. ||2||You are my nine treasures, You are my storehouse.I am imbued with Your Love; You are the Support of my mind.You are my Glory; I am blended with You.You are my Shelter; You are my Anchoring Support. ||3||Deep within my mind and body, I meditate on You.I have obtained Your secret from the Guru.Through the True Guru, the One and only Lord was implanted within me;servant Nanak has taken to the Support of the Lord, Har, Har, Har. ||4||18||87||I do not fear God, I love God. God is not an imperial overlord, God is my support, I can lean on Waheguru at anytime in my life, I can tap into that infinite power-source and overcome any hurdle in front of me.
The Sikh holy text, Sri Guru Granth Sahib Ji, is not a book of rules, regulation, punishment, rewards. It is a tool-box. It is not supposed to dictate your life, it is supposed to enhance it. It has answers for a lot of the important questions in life, and acts as a lamp on your journey to unearth the remaining truths of life. I do not live my life in fear, I read Guru Granth Sahib Ji, contemplate what it Guru Ji is trying to say and make an effort to apply that knowledge to my own life, this isn't a game of carrot and stick, we are all promised two things: a birth, and a death. I rely upon Guru Granth Sahib Ji to carry me across this river of life, to make the most of my short time in this amazingly beautiful Universe.
This will be unsatisfactory for anyone who believes that spiritual authority/morality need to be funneled to humans from a "greater force".
Guru Nanak depended on inquiry, observation, perception of patterns and intelligent propositions. He applied his "hypothesis" to the world of human suffering, asking questions such as how moral or political bankruptcy could be responsible for human suffering. In most shabads (hymns), Guru Nanak asks a moral/ethical question, and answers using patterns of greed, anger, lust, ego and attachment. He suggests that these patterns lie behind the suffering inflicted on ordinary people, and also behind the suffering we inflict on ourselves.
In this way, I do not feel like Sikhi was "revealed" to Guru Nanak, at least in the same way Moses claims to have gotten his revelations from God or Muhammad from the angel Gabriel.
I choose to evaluate the validity of a message by considering it's intelligibility, whether it makes sense, and whether people are free to follow it or are forced to follow it. I believe that Guru Nanak's message is intelligible and it connects with humanity. The bhagats stressed that people had to seek them out for enlightenment, Guru Nanak never made such claims. The Muslim overlords of the time mandated submission to Allah, Guru Nanak never made anyone do anything they did not want to. He reasoned with people, taught them to rely on themselves, that God is found within, he did not speak of damnation, he spoke of God as a "raft" that would take each of us across the ocean of life.
The authority of a scientific model and that of Guru Nanak are essentially the same: Does the message have internal consistency? Does it describe and explain a problem using observations and patterns from the reality before us in a way that rings true? Can we see how moral and ethical problems work? In my opinion, the answer, regarding Guru Nanak, is yes.
Many Sikhs believe Guru Nanak to have gotten direct revelations from God. I do not. To me, this is his greatest strength. Following orders from on high, taking a message from an external authority, leads to obedience; neither morality nor ethics is about obedience. Morality and ethics require a reasoning mind. Guru Nanak taught us to question everything, protect truth and use our reason/logic in everyday life. Pretty much, the same thing someone like Richard Dawkins would advocate:
http://www.youtube.com/watch?v=zSYosM2ZhzYWe need to rely upon our own judgement of what we know to be right and wrong, true and false, and work within that. I will not follow any so-called "prophet" who claims to be in communion with something divine if the message being preached is irrational and goes against everything my conscious knows to be good and bad.
Simply put, Sikhi does not ask me to believe in anything I know to be false (miracles), it treats me like an adult by telling me I am responsible for my own actions, I do something good because I know it is the right thing to do, not because I want a reward and that if I want something, I must work for it with everything I have. Sikhi has taught me to love life, not hate it.
Sorry for making it so long, again, all of this is based on my understanding and interpretation of Sri Guru Granth Sahib Ji and the philosophy of the Gurus. I do not claim to speak for anyone else.