in agreement with the above posts, desire is not, in and of itself a sin... in the case of a Christian longing to be in heaven, it is a good and right desire, placed in the hearts of God's children to want to be where He is, to have, finally, unhindered fellowship with our Creator, the Maker of the Universe, such that our sinfulness no longer interferes with our wants and desires, heaven happens to be where this sort of activity takes place....
and excellent online book I would commend to you is John Piper's "Desiring God", the opening line says this:
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This is a serious book about being happy in God. It's about happiness because that is what our Creator commands: "Delight yourself in the Lord!" ( Psalm 37:4). And it is serious because, as Jeremy Taylor said, "God threatens terrible things if we will not be happy.""
Another interseting quote pertaining to man's desires is where Piper refers to Blaise Pascal;
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All men seek happiness. This is without exception. Whatever different means they employ, they all tend to this end. The cause of some going to war, and of others avoiding it, is the same desire in both, attended with different views. The will never takes the least step but to this object. This is the motive of every action of every man, even of those who hang themselves."
So the question is not if men seek for happiness, it is rather, where will they find it? So the subject of Desiring God, of desiring heaven, is extrmely important for it asks us where we find our happiness, and points out that we are far too easily satisfied with the things of this world, and instead, we ought to be desiring the greater things, in this case the germane point is fellowship with God in heaven... one more quote, this time from CS Lewis....:
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If you asked twenty good men today what they thought the highest of the virtues, nineteen of them would reply, Unselfishness. But if you asked almost any of the great Christians of old he would have replied, Love. You see what has happened? A negative term has been substituted for a positive, and this is of more than philological importance. The negative ideal of Unselfishness carries with it the suggestion not primarily of securing good things for others, but of going without them ourselves, as if our abstinence and not their happiness was the important point. I do not think this is the Christian virtue of Love. The New Testament has lots to say about self-denial, but not about self-denial as an end in itself. We are told to deny ourselves and to take up our crosses in order that we may follow Christ; and nearly every description of what we shall ultimately find if we do so contains an appeal to desire. [/font]
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If there lurks in most modern minds the notion that to desire our own good and earnestly to hope for the enjoyment of it is a bad thing, I submit that this notion has crept in from Kant and the Stoics and is no part of the Christian faith. Indeed, if we consider the unblushing promises of reward and the staggering nature of the rewards promised in the Gospels, it would seem that Our Lord finds our desires not too strong, but too weak. We are half-hearted creatures, fooling about with drink and sex and ambition when infinite joy is offered us, like an ignorant child who wants to go on making mud pies in a slum because he cannot imagine what is meant by the offer of a holiday at the sea. We are far too easily pleased"
see http://www.desiringgod.org/dg/id63.htm
for the whole book, available for free online.....
blessings
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