At what time the first day of the week came into notice as a festival in the church, it is not easy to determine. The first intimation we have of this, in any ancient writer of acknowledged integrity, is from Justin Martyr's Apology for the Christians, about A. D. 140. He is cited as saying, "that the Christians in the city and in the country assembled on the day called Sunday, and after certain religious devotions, all returned home to their labors;" and he assigns as reasons for this, that God made the world on the first day, and that Christ first showed himself to his disciples on that day after his resurrection. These were the best, and probably all the reasons that could then be offered for the practice. He also speaks of Sunday only as a festival, on which they performed labor, when not engaged in devotions, and not as a substitute for the Sabbath. From this author we can learn nothing as to the extent of the practice; for though he says this was done by those "in the city and in the country," he may have intended only the city of Rome and its suburbs, since _Justin_, although a native of Palestine in Syria, is stated by _Eusebius_ to have made his residence in Rome. Nor can we determine from this, that he intended any thing more than that they did thus on the Sunday in which the church of Rome, a short time after this, is known to have closed the paschal feast, which was observed annually. It is contended, however, that mention is made of keeping the first day previous to _Justin_. The first intimation of this kind, it is believed, is from an apocryphal writing, styled the _Epistle of Barnabas_; but to this epistle it is objected, that there is no evidence of its genuineness. _Eusebius_, who lived near the time when it was written, mentions it as a spurious writing, entitled to no credit. _Dr. Milnor_ says it is an injury to St. Barnabas to ascribe this epistle to him. _Mosheim_ says it is the work of some superstitious Jew of mean abilities. And we think it has but little to recommend it besides its antiquity. Barnabas' theory for observing the first day, rests upon the tradition that the seventh day was typical of the seventh millennium of the age of the world, which would be purely a holy age, and that the Sabbath was not to be kept until that time arrived; and he says, "We keep the eighth day with gladness, in which Jesus rose from the dead."