Recently a friend sent me a link to Reserve a Spot in Heaven. This website purports to sell reservations for the hereafter in heaven, complete with certificates and credentials. Naturally I went immediately to their disclaimer page. There I read the truth: "We in no way can guarantee someone entry into heaven." To be fair, they do offer a refund to anyone who buys their "humorous gag gift" and then "in fact did not get into heaven."
The theological problems with this whole thing are many. First of all, heaven is not something to be desired for itself. We are called in this life to love God and to accept his love for us and our fellow creatures. If we soften our hearts and daily dispositions in this way, we hope that our birth into eternal life will be the same in kind. That's what we call our new life in the eternity of God. If we spend our lives turning against God's love and closing ourselves to compassion for each other, we run the risk of making ourselves so indisposed to Love that we will reject God in finality. And that's what we call hell.
Second, the whole gag is based on the idea of a scarcity of grace, as if there was only so much "room" in heaven and we had better reserve our own spot now. With apologies to those who read Revelation 17 to suggest that only the 144,000 will be saved in the final end, grace and salvation are never scarce but rather super-abundant. As one of my teachers from theology likes to say, "grace is free, but it's not cheap."
There are no reservations for heaven. But there are tastes and glimpses that will make us desire it. And the desire for the presence of God and the Presence itself are nearly the same thing, because God is a consuming fire and a burning passion.