The Lord thy God walketh in the midst of thy camp to deliver thee - Deuteronomy 23:14

At all times Israel needed to keep from evil, but especially when her embattled hosts went forth to war; for in the conception of her prophets and saints her battles were not to be fought or won by herself. The Lord God of hosts was there. It was a joint campaign. This was specially revealed to Joshua, when he beheld the captain of the Lord's host, with a drawn sword, beside him. So, Christian soul, remember, in thy war against the evil of the world, and the solicitations of thine own wicked heart, that the battle is not yours, but God's. He is in the midst of thee; thou nee&st not be moved! He has sworn to deliver thee by His own right hand, and by His holy arm, and to give up thine enemies before thee.
 
There was one condition, however, on which the presence of God amongst His people was possible - the camp must be holy. No unclean thing might be seen in any of its borders. The vail of mother-earth must cover all impurity. Thus, as God went up and down the long avenues of the tents, He would see nothing to offend His gaze and make Him turn away. How deep a lesson! God is ever patrolling the avenues of our life. The most secret processes o.f our daily existence, our innermost relationships, the thoughts and intents of our heart, are all manifest to Him. There must be nothing to make Him turn away in holy abhorrence, else we cannot count on Him to deliver us, to give up our enemies before us.
 
"Search me, O God, and know my heart:
Try me, and know my thoughts:
And see if there be any wicked way in me,
And lead me in the way everlasting."