Who is God

Jeremiah 9:24
but let him who boasts boast of this, that he understands and knows Me, that I am the LORD who exercises lovingkindness, justice and righteousness on earth; for I delight in these things," declares the LORD.

One way to describe God is to discuss his attributes. He is perfect in his wisdom, perfect in his lovingkindness, perfect in holiness and righteousness, perfect in justice, perfect in wrath, perfectly faithful, perfect goodness. Those are a few of the ways that God is described in the Bible.

God's perfect faithfulness means that he always does what he says. His perfect righteousness doesn't allow any tolerance of sin. The Jews in Jesus' time got the idea that since they were God's Chosen People, they could pretty much do what they wanted, and God would wink at thier sin. They misjuged the holiness of God. Today we also get the idea that just because we believe that Jesus was the Son of God, that God will wink at our sin. We misjudge the holiness of God when we do that.

God gave us the Bible partially to reveal himself to us. God gave us a lot of examples of how seriously He takes sin.

In Genesis 6, we are told, "5 Then the Lord saw that the wickedness of man was great on the earth, and that every intent of the thoughts of his heart was only evil continually. 6 The Lord was sorry that He had made man on the earth, and He was grieved in His heart. 7 The Lord said, “I will blot out man whom I have created from the face of the land, from man to animals to creeping things and to birds of the sky; for I am sorry that I have made them.” 8 But Noah found favor in the eyes of the Lord." The whole world, except for Noah and his family were wiped out because of sin.

1 Samuel 6 tells a story of men struck down by God for messing with the Ark of the Covenant: "19 He struck down some of the men of Beth-shemesh because they had looked into the ark of the Lord. He struck down of all the people, 50,070 men, and the people mourned because the Lord had struck the people with a great slaughter. 20 The men of Beth-shemesh said, “Who is able to stand before the Lord, this holy God? And to whom shall He go up from us?”

In the Book of Revelation, we are shown what will happen when Jesus returns and the earth is judged for rejecting Him.
Revelation 8:6 "And the seven angels who had the seven trumpets prepared themselves to sound them.
7 The first sounded, and there came hail and fire, mixed with blood, and they were thrown to the earth; and a third of the earth was burned up, and a third of the trees were burned up, and all the green grass was burned up.
8 The second angel sounded, and something like a great mountain burning with fire was thrown into the sea; and a third of the sea became blood, 9 and a third of the creatures which were in the sea and had life, died; and a third of the ships were destroyed.
10 The third angel sounded, and a great star fell from heaven, burning like a torch, and it fell on a third of the rivers and on the springs of waters. 11 The name of the star is called Wormwood; and a third of the waters became wormwood, and many men died from the waters, because they were made bitter.
12 The fourth angel sounded, and a third of the sun and a third of the moon and a third of the stars were struck, so that a third of them would be darkened and the day would not shine for a third of it, and the night in the same way.
13 Then I looked, and I heard an eagle flying in midheaven, saying with a loud voice, “Woe, woe, woe to those who dwell on the earth, because of the remaining blasts of the trumpet of the three angels who are about to sound!”

But that is mild compared to what is described in the rest of the book. The point is that God does not take our sin lightly. His perfect holiness cannot tolerate evil and his perfect justice does not allow evil to go unpunished.

God's perfect goodness is shown to be unattainable by man on his own. Jesus defined what being "good" means to God:

Matthew 5 20 “For I say to you that unless your righteousness surpasses that of the scribes and Pharisees, you will not enter the kingdom of heaven.
21 “You have heard that the ancients were told, ‘You shall not commit murder’ and ‘Whoever commits murder shall be liable to the court.’ 22 But I say to you that everyone who is angry with his brother shall be guilty before the court; and whoever says to his brother, ‘You good-for-nothing,’ shall be guilty before the supreme court; and whoever says, ‘You fool,’ shall be guilty enough to go into the fiery hell. 23 Therefore if you are presenting your offering at the altar, and there remember that your brother has something against you, 24 leave your offering there before the altar and go; first be reconciled to your brother, and then come and present your offering. 25 Make friends quickly with your opponent at law while you are with him on the way, so that your opponent may not hand you over to the judge, and the judge to the officer, and you be thrown into prison. 26 Truly I say to you, you will not come out of there until you have paid up the last cent.
27 “You have heard that it was said, ‘You shall not commit adultery’; 28 but I say to you that everyone who looks at a woman with lust for her has already committed adultery with her in his heart. 29 If your right eye makes you stumble, tear it out and throw it from you; for it is better for you to lose one of the parts of your body, than for your whole body to be thrown into hell. 30 If your right hand makes you stumble, cut it off and throw it from you; for it is better for you to lose one of the parts of your body, than for your whole body to go into hell.
31 “It was said, ‘Whoever sends his wife away, let him give her a certificate of divorce’; 32 but I say to you that everyone who divorces his wife, except for the reason of unchastity, makes her commit adultery; and whoever marries a divorced woman commits adultery.
33 “Again, you have heard that the ancients were told, ‘You shall not make false vows, but shall fulfill your vows to the Lord.’ 34 But I say to you, make no oath at all, either by heaven, for it is the throne of God, 35 or by the earth, for it is the footstool of His feet, or by Jerusalem, for it is the city of the great King. 36 Nor shall you make an oath by your head, for you cannot make one hair white or black. 37 But let your statement be, ‘Yes, yes’ or ‘No, no’; anything beyond these is of evil.
38 “You have heard that it was said, ‘An eye for an eye, and a tooth for a tooth.’ 39 But I say to you, do not resist an evil person; but whoever slaps you on your right cheek, turn the other to him also. 40 If anyone wants to sue you and take your shirt, let him have your coat also. 41 Whoever forces you to go one mile, go with him two. 42 Give to him who asks of you, and do not turn away from him who wants to borrow from you.
43 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ 44 But I say to you, love your enemies and pray for those who persecute you, 45 so that you may be sons of your Father who is in heaven; for He causes His sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous. 46 For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? 47 If you greet only your brothers, what more are you doing than others? Do not even the Gentiles do the same? 48 Therefore you are to be perfect, as your heavenly Father is perfect.

Luke 6 27 “But I say to you who hear, love your enemies, do good to those who hate you, 28 bless those who curse you, pray for those who mistreat you. 29 Whoever hits you on the cheek, offer him the other also; and whoever takes away your coat, do not withhold your shirt from him either. 30 Give to everyone who asks of you, and whoever takes away what is yours, do not demand it back. 31 Treat others the same way you want them to treat you. 32 If you love those who love you, what credit is that to you? For even sinners love those who love them. 33 If you do good to those who do good to you, what credit is that to you? For even sinners do the same. 34 If you lend to those from whom you expect to receive, what credit is that to you? Even sinners lend to sinners in order to receive back the same amount. 35 But love your enemies, and do good, and lend, expecting nothing in return; and your reward will be great, and you will be sons of the Most High; for He Himself is kind to ungrateful and evil men. 36 Be merciful, just as your Father is merciful.
37 “Do not judge, and you will not be judged; and do not condemn, and you will not be condemned; pardon, and you will be pardoned. 38 Give, and it will be given to you. They will pour into your lap a good measure—pressed down, shaken together, and running over. For by your standard of measure it will be measured to you in return.”

When we try and attain this righteousness on our own, we fail. The only thing we can do is throw ourselves on the mercy of the Judge, ask his forgiveness, and accept the payment Jesus made on the cross to atone for our crimes. When we do this, God sees us as having lived Jesus' sinless life, instead of our own.

http://www.gty.org/resources/sermons/45-76/israels-failure-part-2?term=4...
http://www.gty.org/resources/sermons/45-77/israels-failure-part-3?term=4...