that God is the most Merceful but also his punishment is the most effective.
This punishment can be avoided if you realized the greatness of your sin and started asking God to forgive you.
here is what prophet Muhammed said

Narrated Abu Huraira:

The people said, "O Allah's Apostle! Shall we see our Lord on the Day of Resurrection?" Prophet Muhammad (peace and blessings upon Him) replied,

"Do you have any doubt in seeing the full moon on a clear (not cloudy) night?" They replied,
"No, O Allah's Apostle!"
He said,
"Do you have any doubt in seeing the sun when there are no clouds?"
They replied in the negative.
He said, "You will see Allah (your Lord) in the same way. On the Day of Resurrection, people will be gathered and He will order the people to follow what they used to worship. So some of them will follow the sun, some will follow the moon, and some will follow other deities; and only this nation (Muslims) will be left with its hypocrites. Allah will come to them and say, 'I am Your Lord.' They will say, 'We shall stay in this place till our Lord comes to us and when our Lord will come, we will recognize Him. Then Allah will come to them again and say, 'I am your Lord.' They will say, 'You are our Lord.' Allah will call them, and As-Sirat (a bridge) will be laid across Hell and I (Muhammad) shall be the first amongst the Apostles to cross it with my followers. Nobody except the Apostles will then be able to speak and they will be saying then, 'O Allah! Save us. O Allah Save us.'

for more
http://www.bellaonline.com/articles/art50609.asp