One trait of God is His omniscience (He is all-knowing). He knows what will happen for all of eternity. The things that man know are not even a tip of a nail compared to what God knows. He even knows what will happen to you a minute from now which you don't have an idea of. That established, atheists and agnostics would argue that God, if He does exists, with His omniscience, should have decided NOT to give man free will because He knows that they'll just use it to rebel against Him which will result to them going to Hell to pay for their sins. If He does exists then He must enjoy seeing people go to Hell?
First of all, the Bible makes it clear that God has no pleasure in seeing sinners die which lead them to eternal punishment (Ezekiel 33:11). He created man for His glory and for His pleasure (Revelations 4:11). Now here's a question... If you're God, will you derive pleasure from the "love" your created gives you if in the first place, you have programmed them like robots to give you love (they have no choice but to love you)? I believe that you'll agree that "love" that's not freely given is not true love. God had to give man a free will so that He can experience true love from His created so that pleasure is achieved. He wanted man to love Him willingly. Free will allows man to love God willingly. That's why God gave us free will. Not doing so goes against reason. God is a logical Person that's why He saw it right to give man the freedom to choose for himself and He hoped that we'd use it to give Him pleasure.
But how about the fact that in man's use of his free will to do evil, it results to suffering in Hell? Shouldn't have God just sacrificed His desire to experience true love from His created so that no one goes to Hell? I believe that God could have chosen to do that... IF He had no power to use evil to bring out good. What do I mean about that? God used the evil of the cross to solve man's problem of sin. The cross is a reflection of all the evil of man. The cross is a picture of what any criminal should deserve. God experienced the cruelty of the cross as if He was a hardened criminal just so He can make a payment for man's sins. Buddha had no solution for the penalty of man's sins. Mohammed offered no real solution either. Catholicism, although claiming to be Christian in beliefs, still gives man a big responsibility in saving himself. The New Age movement can only suggest something that will make you focus on the "here and now" so that you'll not be burdened with what's ahead in eternity. This makes Christianity unique. It offered a solution. Jesus was the solution. God turned evil to good by transferring all of man's evil on His beloved Son so He could pay for them. The chains of sin on us were broken because Jesus let himself experience the evil of men.
God still uses evil in our time to bring out good. How many people have turned to God for assurance of life in Heaven after they've realized how fragile and short life is through the death of someone they know? I believe you and your other Christian friends can name some. God uses natural calamities like the tsunami in Japan and the big earthquakes that rocked major cities early this year to bring to the minds of people that there is a powerful God that they should fear, or better yet, be reconciled with. Crimes around us, heavy and petty crimes alike, show how man has gone low in their morals, and therefore, disqualifies them from the future joys of Heaven. Your own offense of God's Moral Standards, the Ten Commandments, should bring you to the realization that you're not a good person, that's why you need Jesus' perfection to be transferred on you to enter into His Kingdom. For Christians, God uses circumstances to bring out new strength from us so that, we, in turn, can also be used by Him to strengthen others. He also uses sufferings to re-focus ourselves to Him so that we can enjoy Him even in this world.
In conclusion, God gave man free will even if He knew it will cause problems through man's wrong use of it because He also knows the solution to it... Jesus. When God finished making this world on the sixth day, He looked on the whole of His creation and saw that it was all good, including the free will He gave man. To you who are still living in sin, use your free will by deciding to forsake your sins and to have Jesus be your Lord and Savior. To us, His children, let us use the free will God gave us to bring pleasure to the only One who can use evil to bring out good for our benefit. Praise be the Lord!