Advent is obviously about waiting. In so far as it is about waiting, it is also about hoping. Christian waiting is not a vague sense that something might happen and we'd better stick around for it. It is the knowledge that the Son of God who came once to bear the sins of many will return to save those who are eagerly waiting for him. That is a certain hope, and it is that hope which informs the character of our waiting. It is not quite the anticipation of a child waiting for Christmas - there is more solemnity to it than that, because we know the gravity of the event for which we wait. Neither is it the frustrated waiting of the man waiting for the bus - we know that Christ is not being held up anywhere, or delayed by anything beyond his will and control. And again, it is not the bored waiting of the woman who just wants this meeting to end - because the person for whom we wait demands that as we wait we also work, joyfully in his service.
It is a waiting coloured by hope, a waiting which takes on the character of the event for which it waits, a waiting which builds in us the character of the one for whom we wait. It is solemn and joyful and resting and confident and active.
And it teaches us to say no.
It is not popular nowadays to point out that Christianity involves a lot of renouncing, a lot of self-limiting, a lot of saying 'no'. Some of that is saying no to things which are bad and destructive, but an awful lot of it is also saying no to things which, in themselves, are good and legitimate enjoyments, but which are not right for us now. It is sacrificing present enjoyment for the future hope. Whether it is the 'no' to food of the Christian committed to fasting, or the 'no' to sex of the Christian committed to celibacy, or the millions of other little 'noes' that build up, this is a life of renunciation. It is a life of denial. And that is okay. Because of the hope. All of this saying 'no' is, in one sense, just waiting - deferring enjoyment and pleasure until he comes.
For the grace of God has appeared, bringing salvation for all people, training us to renounce ungodliness and worldly passions, and to live self-controlled, upright, and godly lives in the present age, waiting for our blessed hope, the appearing of the glory of our great God and Saviour Jesus Christ, who gave himself for us to redeem us from all lawlessness and to purify for himself a people for his own possession who are zealous for good works.