Due to living in a hostile, anti-Christian environment with Indians who did not know the Lord, the New England Puritans thought it best to come to services armed in order to protect their fellow Christians from attack.
The following account by Alice Morse Earle in "The Sabbath in Puritan New England," discusses this in detail, and explains the tradition of men sitting on the ends of the pews so they could quickly grab their arms in the case of attack.
For many years after the settlement of New England the Puritans, even in outwardly tranquil times, went armed to meeting; and to sanctify the Sunday gun-loading they were expressly forbidden to fire off their charges at any object on that day save an Indian or a wolf, their two "greatest inconveniencies." Trumbull, in his "Mac Fingal," writes thus in jest of this custom of Sunday arm-bearing:--
"So once, for fear of Indian beating,
Our grandsires bore their guns to meeting,--
Each man equipped on Sunday morn
With psalm-book, shot, and powder-horn,
And looked in form, as all must grant,
Like the ancient true church militant."
In 1640 it was ordered in Massachusetts that in every township the attendants at church should carry a "competent number of peeces, fixed and compleat with powder and shot and swords every Lords-day to the meeting-house;" one armed man from each household was then thought advisable and necessary for public safety. In 1642 six men with muskets and powder and shot were thought sufficient for protection for each church.
In Connecticut, similar mandates were issued, and as the orders were neglected "by divers persones," a law was passed in 1643 that each offender should forfeit twelve pence for each offence. In 1644 a fourth part of the "trayned hand" was obliged to come armed each Sabbath, and the sentinels were ordered to keep their matches constantly lighted for use in their match-locks.
They were also commanded to wear armor, which consisted of "coats basted with cotton-wool, and thus made defensive against Indian arrows." In 1650 so much dread and fear were felt of Sunday attacks from the red men that the Sabbath-Day guard was doubled in number. In 1692, the Connecticut Legislature ordered one fifth of the soldiers in each town to come armed to each meeting, and that nowhere should be present as a guard at time of public worship fewer than eight soldiers and a sergeant. In Hadley the guard was allowed annually from the public treasury a pound of lead and a pound of powder to each soldier.
No details that could add to safety on the Sabbath were forgotten or overlooked by the New Haven church; bullets were made common currency at the value of a farthing, in order that they might be plentiful and in every one's possession; the colonists were enjoined to determine in advance what to do with the women and children in case of attack, "that they do not hang about them and hinder them;" the men were ordered to bring at least six charges of powder and shot to meeting; the farmers were forbidden to "leave more arms at home than men to use them;" the half-pikes were to be headed and the whole ones mended, and the swords "and all piercing weapons furbished up and dressed;" wood was to be placed in the watch-house; it was ordered that the "door of the meeting-house next the soldiers' seat be kept clear from women and children sitting there, that if there be occasion for the soldiers to go suddenly forth, they may have free passage." The soldiers sat on either side of the main door, a sentinel was stationed in the meeting-house turret, and armed watchers paced the streets; three cannon were mounted by the side of this "church militant," which must strongly have resembled a garrison. ...
In spite of these events in the New Haven church (which were certainly exceptional), the seemingly incongruous union of church and army was suitable enough in a community that always began and ended the military exercises on "training day" with solemn prayer and psalm-singing; and that used the army and encouraged a true soldier-like spirit not chiefly as aids in war, but to help to conquer and destroy the adversaries of truth, and to "achieve greater matters by this little handful of men than the world is aware of."
The Salem sentinels wore doubtless some of the good English armor owned by the town,--corselets to cover the body; gorgets to guard the throat; tasses to protect the thighs; all varnished black, and costing each suit "twenty-four shillings a peece." The sentry also wore a bandileer, a large "neat's leather" belt thrown over the right shoulder, and hanging down under the left arm. This bandileer sustained twelve boxes of cartridges, and a well-filled bullet-bag. Each man bore either a "bastard musket with a snaphance," a "long fowling-piece with musket bore," a "full musket," a "barrell with a match-cock," or perhaps (for they were purchased by the town) a leather gun (though these leather guns may have been cannon). Other weapons there were to choose from, mysterious in name, "sakers, minions, ffaulcons, rabinets, murthers (or murderers, as they were sometimes appropriately called) chambers, harque-busses, carbins," ...
The armed Salem watcher, besides his firearms and ammunition, had attached to his wrist by a cord a gun-rest, or gun-fork, which he placed upon the ground when he wished to fire his musket, and upon which that constitutional kicker rested when touched off. He also carried a sword and sometimes a pike, and thus heavily burdened with multitudinous arms and cumbersome armor, could never have run after or from an Indian with much agility or celerity; though he could stand at the church-door with his leather gun,--an awe-inspiring figure,--and he could shoot with his "harquebuss," or "carbin," as we well know.