t I may call this drill-book for the Christian
warfare, which is the Christian life.

'Watch ye.' That means one of two things certainly, probably
both--Keep awake, and keep your eyes open. Our Lord used the same
metaphor, you remember, very frequently, but with a special
significance. On His lips it generally referred to the attitude of
expectation of His coming in judgment. Paul uses sometimes the figure
with the same application, but here, distinctly, it has another. As I
said, there is the military idea underlying it. What will become of
an army if the sentries go to sleep? And what chance will a Christian
man have of doing his _devoir_ against his enemy, unless he
keeps himself awake, and keeps himself alert? Watchfulness, in the
sense of always having eyes open for the possible rush down upon us
of temptation and evil, is no small part of the discipline and the
duty of the Christian life. One part of that watchfulness consists in
exercising a very rigid and a very constant and comprehensive
scrutiny of our motives. For there is no way by which evil creeps
upon us so unobserved, as when it slips in at the back door of a
specious motive. Many a man contents himself with the avoidance of
actual evil actions, and lets any kind of motives come in and out of
his mind unexamined. It is all right to look after our _doings_, but
'as a man _thinketh_ in his heart, so is he.' The good or the evil of
anything that I do is determined wholly by the motive with which I do
it. And we are a great deal too apt to palm off deceptions on
ourselves to make sure that our motives are right, unless we give
them a very careful and minute scrutiny. One side of this
watchfulness, then, is a habitual inspection of our motives and
reasons for action. 'What am I doing this for?' is a question that
would stop dead an enormous proportion of our activity, as if you had
turned the steam off from an engine. If you will use a very fine
sieve through which to strain your motives, you will go a long way to
keeping your actions right. We should establish a rigid examination
for applicants for entrance, and make quite sure that each that
presents itself is not a wolf in sheep's clothing. Make them all
bring out their passports. Let every vessel that comes into your
harbour remain isolated from all communication with the shore, until
the health officer has been on board and given a clean bill. 'Watch
ye,' for yonder, away in the dark, in the shadow of t