It said whoever. That means anybody and everybody.
It says "whosoever believes in (on) Him", which most certainly does not mean everybody, because only a remnant will be in heaven.
Look, I am a Calvinist and I believe in "free will". Of course a choice has to be made by us. I believe that choice is prompted by the Holy Spirit when presented with the Gospel. Obviously, "whosoever believes in Him" can be limited to those He has prompted to choose Him, because they are necessarily the "whosoever" that HAVE believed in or on Him.
Hayes hit the nail on the head above. It really boils down to semantics.
I grew up Baptist (in a very staunch Baptist family), and probably re-dedicated my life to Christ 10 times as a youth. It was so hard to be sure I was saved because my life was filled with sin. Why would God save me, had I really trusted in Him, etc...? In college I started going to Reformed University Fellowship (RUF - Run by PCA Church) mainly because there were hot girls there. I befriended the minister and we would have hours long discussion (arguments) over the topic of predestination. At his request, I read several, several books on the subject as well as extensive Bible reading. The result...you cannot deny the logic (IMHO), you cannot deny the scripture (IMHO) and there is a relative misunderstanding of Predestination because as good Baptist we are taught that it is a bad word.
To me it is the best thing in the world to realize that by God's Grace, he choose me to follow Him, not the other way around, because as a person riddled with sin, I will choose the wrong thing everytime. Do I deserved to be saved more than the next guy...no way. I am no better than anyone...a wretched sinner. That is the beauty of grace.
Finally and ultimately, I believe that all Christians are going to heaven.