11 Day after day every priest stands and performs his religious duties; again and again he offers the same sacrifices, which can never take away sins. 12 But when this priest had offered for all time one sacrifice for sins, he sat down at the right hand of God, 13 and since that time he waits for his enemies to be made his footstool. 14 For by one sacrifice he has made perfect forever those who are being made holy.
15 The Holy Spirit also testifies to us about this. First he says:
16
“This is the covenant I will make with them
after that time, says the Lord.
I will put my laws in their hearts,
and I will write them on their minds.”[b]
17 Then he adds:
“Their sins and lawless acts
I will remember no more.”[c]
18 And where these have been forgiven, sacrifice for sin is no longer necessary.
There is nothing lacking in the sacrifice of Jesus with regards for paying for sins. One sacrifice was sufficient to pay for the justification and sanctification of believers forever. The sacrifice need not and cannot be repeated and this point is stressed repeatedly in the book of Hebrews. Any suggestion that the atonement of Christ was not sufficient to pay for all past, present and future sins of believers is an insult to our Lord. His sacrifice was of infinite worth and he lived in the flesh as a perfect man, and in his spirit he was God the Word. He sat down at God’s right hand after. The work was done forever.
The passage quoted in the opening article is about the (necessary) suffering of the apostles and all believers in providing an ongoing example of the selflessness and devotion we have towards Christ in following his footsteps. The sacrifice of Christ was enough to deal with sin, but the suffering of his saints is required to testify to the world over and over the example of the suffering of Christ and the willingness of his people to share in his suffering to show again his love and mercy.
The passage I quoted is from Hebrews 10. Reading the entire epistle is recommended though.