Imagine for a moment you were immortal. Your body could not be broken. Your skin can not be pierced.
You can still, for example, drown... but you wont die. You would fall into the water, your lungs would take in water, you would be in pain, but, you would not die. You could also be in space, and not die, or on fire, and not die.
Now, lets say I wanted to torture you. I thus, toss you into the sun. Thousands of degrees of heat... or is it Millions? Well it's very hot regardless. The gravity would pull you down and the pressure would crush you. You would be in endless burning pain, never to be able to escape until the sun burns out in billions of years.
This is crazy right? How could I do such a thing? What kind of terrible person can I be to think of doing this. What kind of horrible person would wish this upon someone?
Well. When I think of this, I think of descriptions of Hell. Eternal torture, pain and suffering.
This is where I like to point out the second half of John 3:16 says that anyone who doubts Jesus goes to hell.
Thus I pose the question: Could God be this Cruel?
It's not cruelty, it's justice. Romans 3:23 says "For all have sinned and come short of the glory of God" and Romans 6:23 says "For the wages of sin is death, but the gift of God is eternal life through Jesus Christ our Lord." The Bible also refers to hell as a place where "the worm dieth not". This scenario of torture you are bringing up is what hell is like, except millions of times worse. However, for those who are believers in Christ Jesus, Romans 8:1 offers this "There is therefore now NO condemnation to those who are in Christ Jesus, who walk not after the flesh, but after the Spirit."
God is not only a loving God, but He is a just God. He is not some cosmic push-over as the world likes to portray, He will one day deal with sin decisively and with finality.