Walk in wisdom toward them that are without, redeeming the time. Walk in wisdom - Act wisely and prudently in reference to them who are without - who yet continue unbelieving Gentiles or persecuting Jews.
The Church of Christ was considered an enclosure; a field, or vineyard, well hedged or walled. Those who were not members of it, were considered without; i.e. not under that especial protection and defense which the true followers of Christ had. This has been since called "The pale of the Church," from palus, a stake; or, as Dr. Johnson defines it, "A narrow piece of wood, joined above and below to a rail, to enclose grounds." As to be a Christian was essential to the salvation of the soul, so to be in the Church of Christ was essential to the being a Christian; therefore it was concluded that "there was no salvation out of the pale of the Church." Now this is true in all places where the doctrines of Christianity are preached; but when one description of people professing Christianity, with their own peculiar mode of worship and creed, arrogate to themselves, exclusive of all others, the title of The Church; and then, on the ground of a maxim which is true in itself, but falsely understood and applied by them, assert that, as they are The Church, and there is no Church besides, then you must be one of them, believe as they believe, and worship as they worship, or you will be infallibly damned; I say, when this is asserted, every man who feels he has an immortal spirit is called on to examine the pretensions of such spiritual monopolists. Now, as the Church of Christ is formed on the foundation of the prophets and apostles, Jesus Christ being the chief corner stone, the doctrines of this Christian Church must be sought for in the sacred Scriptures. As to fathers, councils, and human authorities of all kinds, they are, in this question, lighter than vanity; the book of God alone must decide. The Church, which has been so hasty to condemn all others, and, by its own soi disant or self-constituted authority, to make itself the determiner of the fates of men, dealing out the mansions of glory to its partisans, and the abodes of endless misery to all those who are out of its antichristian and inhuman pale; this Church, I say, has been brought to this standard, and proved by the Scriptures to be fallen from the faith of God's elect, and to be most awfully and dangerously corrupt; and to be within its pale, of all others professing Christianity, would be the most likely means of endangering the final salvation of the soul. Yet even in it many sincere and upright persons may be found, who, in spirit and practice, belong to the true Church of Christ. Such persons are to be found of all religious persuasions, and in all sorts of Christian societies.
Redeeming the time - See on Ephesians 5:16 (note).