New Testament

1 Peter 4:6

4 So they are astonished when you do not rush with them into the same flood of wickedness, and they vilify you. 5 They will face a reckoning before Jesus Christ who stands ready to judge the living and the dead. 6 Now it was for this very purpose that the gospel was preached to those who are now dead, so that though they were judged in the flesh by human standards they may live spiritually by God’s standards. 7 For the culmination of all things is near. So be self-controlled and sober-minded for the sake of prayer. 8 Above all keep your love for one another fervent because love covers a multitude of sins.

Date: 60-65 C.E. (If authentic), 80-90 C.E. (If anymous)
* Dates are based on scholarly estimates

Tertullian Concerning the Soul 55:3

By ourselves the lower regions (of Hades) are not supposed to be a bare cavity, nor some subterranean sewer of the world, but a vast deep space in the interior of the earth, and a concealed recess in its very bowels; inasmuch as we read that Christ in His death spent three days in the heart of the earth, that is, in the secret inner recess which is hidden in the earth, and enclosed by the earth, and superimposed on the abysmal depths which lie still lower down. Now although Christ is God, yet, being also man, He died according to the Scriptures, and according to the same Scriptures was buried. With the same law of His being He fully complied, by remaining in Hades in the form and condition of a dead man; nor did He ascend into the heights of heaven before descending into the lower parts of the earth, that He might there make the patriarchs and prophets partakers of Himself. (This being the case), you must suppose Hades to be a subterranean region, and keep at arm's length those who are too proud to believe that the souls of the faithful deserve a place in the lower regions. These persons, who are servants above their Lord, and disciples above their Master, would no doubt spurn to receive the comfort of the resurrection, if they must expect it in Abraham's bosom.

Date: 198-200 C.E.
* Dates are based on scholarly estimates