My friend, what are you building? A prison; a mere garden-house of lustful delights; or a temple fortress in which God may dwell reverenced, and you may abide restful? Observe that whilst all men are thus unconsciously and habitually rearing up a permanent abode by their transient actions, every life that is better than a brute's ought to have for its aim the building up of ourselves into firm strength. The development of character is what we ought to ask from, and to secure by, this fleeting life of ours. Not enjoyment; that is a miserable aim. Not the satisfaction of earthly desires; not the prosperity of our business or other ordinary avocations. The demand that we should make upon life, and the aim which we should have clearly before us in all that we do, is that it may contribute to the formation of a pure and noble self, to the development of character into that likeness to Jesus Christ, which is perfection and peace and blessedness. And while that is true about all life, it is eminently true in regard to the highest form of life, which is the Christian life. There are dreadful mistakes and imperfections in the ordinary vulgar conception of what a Christian is, and what he is a Christian for. What do you think men and women are meant to be Christians for? That they may get away from some material and outward hell? Possibly. That they may get celestial happiness? Certainly. But are these the main things? By no means. What people are meant to be Christians for is that they may be shaped into the likeness of Jesus Christ; or to go back to the metaphor of my text, the meaning and aim of Christian discipleship is not happiness, but the building up of the tower in which the man may dwell. Ah, friend; is that your notion of what a Christian is; and of what he is a Christian for, to be like the Master? Alas! alas! how few of us, honestly and continually and practically, lay to heart the stringent and grand conception which underlies this metaphor of our Lord's, who identifies the man that was thinking of being His disciple with the man that sits down intending to build a tower. II. So, secondly, note the cost of the building, or the conditions of discipleship. Building is an expensive amusement, as many a man who has gone rashly in for bricks and mortar has found out to his cost. And the most expensive of all sorts of building is the building up of Christian character. That costs more than anything else, but there are a number of other things less noble and desirable, which share with it, to some extent, in the expenditure which it involves.