The age of service fixed for the men of the tribes may yield suggestions for our time. It is not of warlike service we have to think, but of that which depends on spiritual influence and intellectual power. And we may ask whether the limits on one side and the other have any parallel for us. Young men and women, having reached the age of bodily and mental vigour, are to hold themselves enrolled in the ranks of the army of God. There is a time of learning and preparation, when knowledge is to be acquired, when the principles of life are to be grasped, and the soul is to find its inspiration through personal faith. Then there should come that self-consecration by which response is made to the claim of God. Neither should that be premature, nor should it be deferred. When an aimless, irresolute adolescence is followed by years of drifting and experimenting without clear religious purpose, the best opportunity of life is thrown away. And this far too frequently occurs among those on whom parental influence and the finest Christian teaching have been expended. The time arrives when such young men and women should begin to serve the Church and the world; but they are still unprepared because they have not considered the great questions of duty, and seen that they have a part to play on the field of endeavour. It is true, no time can be fixed. The public service of Christ has been begun by some in very early youth; and the results have justified their adventure. From the humble tasks they first undertook they have gone on steadily to places of high responsibility, never once looking back, learning while they taught, gaining faith while they imparted it to others. Each for himself or herself, in this matter of supreme importance, must seek the guidance and realise the vocation of God. But delay is often indulged, and the twentieth, even the thirtieth year, passes without a single effort in the holy service. One could wish for a Divine conscription, a command laid on every one in youth to be ready at a certain day and hour to take the sword of the Spirit.
On the other side also many need to reconsider. No time was fixed for the end of the services to which the Israelites were summoned. As long as a man could carry arms he was to hold himself ready for the field. Not the increasing cares of his family, not the disinclination which comes with years, was to weigh against the ordinance of Jehovah. But service now, however cheerfully it may be rendered in early manhood and womanhood, is often renounced altogether when knowledge and power are coming to ripeness with the experience of life. Doubtless there are many excuses to be made for heads of households who are leaving their young folk to represent them in religion, and pretty much in everything outside the mere maintaining of existence or the enjoyment of it. The demands of public service all round are sometimes quite out of proportion to the available time and strength. Yet the Christian duty never lapses; and it is a great evil when the balance is wanting between old and young, tried and untried.