At 2 Corinthians 6:2 the apostle Paul quotes from the prophecy of Isaiah 49:8, which says: “This is what Jehovah has said: ‘In a time of goodwill I have answered you, and in a day of salvation I have helped you; and I kept safeguarding you that I might give you as a covenant for the people, to rehabilitate the land, to bring about the repossessing of the desolated hereditary possessions.’” In its original setting this statement was evidently made to Isaiah as representing or personifying the nation of Israel. (Isa 49:3) It was clearly a restoration prophecy and, hence, had its first fulfillment at the time of the liberation of Israel from Babylon when the call went to the Israelite prisoners, “Come out!” They thereafter returned to their homeland and rehabilitated the desolated land.​—Isa 49:9.

However, the words “that I might give you as a covenant for the people” in verse 8 of this chapter and the preceding statement in verse 6 that this “servant” of Jehovah would be given as “a light of the nations, that [God’s] salvation may come to be to the extremity of the earth,” definitely mark the prophecy as Messianic and as therefore applying to Christ Jesus as God’s “servant.” (Compare Isa 42:1-4, 6, 7 with Mt 12:18-21.) Since the “time of goodwill” was a time when Jehovah would ‘answer’ and ‘help’ his servant, it must apply to Jesus’ earthly life when he “offered up supplications and also petitions to the One who was able to save him out of death, with strong outcries and tears, and he was favorably heard for his godly fear.” (Heb 5:7-9; compare Joh 12:27, 28; 17:1-5; Lu 22:41-44; 23:46.) It was, therefore, “a day of salvation” for God’s own Son, during which period of opportunity he demonstrated perfection of integrity and, as a result, “became responsible for everlasting salvation to all those obeying him.”​—Heb 5:9.

Additionally, Paul’s quotation from this prophecy indicates a still further application to those Christians whom Paul urges “not to accept the undeserved kindness of God and miss its purpose,” and to whom he says (after quoting Isa 49:8): “Look! Now is the especially acceptable time. Look! Now is the day of salvation.” (2Co 6:1, 2) Such Christians had become the spiritual “Israel of God” from Pentecost of 33 C.E. forward (Ga 6:16), but there was a need for them to prove worthy of God’s undeserved kindness, so that the “acceptable time” might indeed prove to be “a day of salvation” for them.

The fact that the prophecy in its original application was one of restoration would likewise indicate an application to a time of release from spiritual captivity and of restoration to full favor with God.​—Compare Ps 69:13-18.

To natural Jews who failed to appreciate the favorableness of the time and the opportunity that was theirs for entry into ‘spiritual Israel,’ Paul announced that he was turning to the non-Jewish nations, and he quoted Isaiah 49:6 in support, saying: “In fact, Jehovah has laid commandment upon us in these words, ‘I have appointed you as a light of nations, for you to be a salvation to the extremity of the earth.’” (Ac 13:47) Since “time” and “day” are terms indicating temporariness, they imply urgency and the need to use wisely an opportune period or season of favor before its end comes bringing the withdrawal of divine mercy and offer of salvation.​—Ro 13:11-13; 1Th 5:6-11; Eph 5:15-20.