Happy are those who repent their sins for they will be forgiven and those who do not confess their sins are troubled since they keep on crying all day long. Those who are forgiven when they pray God is ready to answer and help them in case of any trouble that come across on their living.
The Lord instructs and advises those who obey His will. Abraham obeyed God and at the end he got blessings. Through the example of Abraham, we learn that obedience is one of the values a Christian has to have to get Godís blessings.
David did worst things than Saul but God preferred David because he had a good heart of repentance. He was willing to be punished for the wrongs he did. And he was forgiven and he received happiness.
Once you repent your sins with a willing heart in need of forgiveness, God shall forgive you and you shall have happiness. When David sinned and did not confess, God punished him day and night, he was weak. But when he repented and confessed, all his sins were forgiven. The Lord says that He will show us the way to go and advice us and give us happiness.