In the old testament, the Lord described a time period in which He would accept man’s repentance and turning to the Messiah’s sacrifice for his salvation. That time period is not forever, nor will the Lord wait any longer than the lifespan of any man. If a person should die without receiving the Messiah’s sacrifice as the payment for their sins, this person will be lost forever, with no hope of redemption.
Genesis 6:3 And the LORD said, “My Spirit shall not strive with man forever, for he is indeed flesh; yet his days shall be one hundred and twenty years.”
The Grace of God, though it is far reaching, long and with great patience, it does have a limit. God will not “strive” with man over his sin and need for salvation forever.
The time period in which God will hear a sinners repentance, and plea for salvation, is now, before any of us die, before the Lord Jesus returns to make final judgment on the world. If anyone should be obstinate and refuse the Lord’s generous offer of forgiveness, there will come a time when it will be too late, and there will be no right of appeal.