The suggestion may often be the result of our past unfaithfulness. It is not always easy to trace the pedigree of a temptation, but in most cases it is highly likely that it is to be traced back to some failure of our own in the past. Men indulge themselves; they whet the imagination with evil thought and conversation and reading. They develop their passions by giving rein to them. By continued failure to resist, they go on in the same sin under many varying conditions, until a hundred commonplace, every-day happenings, entirely innocent in themselves, become charged with sinful suggestions, recalling the old sin whenever they occur. It is as though a commander should plant powerful batteries about his own fortress, preparing them to be used by the enemy. Thus learning from our past, we know how to guard ourselves for the future. Present faithfulness is the pledge, and the only pledge, of future security.[4] {112} Or it may be that Satan, accustomed to success in leading us astray in certain things, is encouraged to suggest like evil to our minds again. However this may be, whether the suggestion arises from the evil bent that our minds have received through former yielding, or whether it be Satan's device and unprovoked solicitation, _there is no sin in the mere fact that evil is suggested to our minds, however persistently or strongly_.[5] In any case it had its origin outside of us, and unless we have deliberately run into the occasion of sin, or in some culpable way invited it, we are in the immediate case not responsible for the suggestion. Therefore, the suggestion can in no way be regarded as sin, for unless our wills have brought it about, or consciously encouraged it, our souls are unstained. Without the action of the will, no sin can enter the heart. "What is done without, or against, our will, rather takes place in us, than is done _by_ us."[6] {113} "No risings, then, of any passion, yea, though it should rise again and again, against thee, and by rising weary thee, and almost wear thee out: no thought by night when thou hast not power over thy soul, and thy will is not conscious: no thoughts by day, which come to thee again and again, and besiege thee and torment thee, and would claim thee for their own: no distractions in prayer, even if they carry thee away, and thou lose thyself and awake, as it were, out of a dream, and thy prayer be gone,--none of these things are thine. Nothing without thy will is thine, or will be imputed to thee. It is not the mere presence with thee of what thou hatest: it is not the recurrence, again and again, of what thou loathest, which will hurt thee: not even if it seems to come from thy inmost self, unless thy will consent to it."[7] II. _The Response of the Natural Heart_