"Jesus Christ is the same yesterday and today and forever." (Hebrews 13:8)
The letter closes with a cluster of practical instructions. Keep on loving one another as brothers and sisters. Show hospitality to strangers, for by so doing some have shown hospitality to angels without knowing it. Continue to remember those in prison as if you were together with them in prison, and those who are mistreated as if you yourselves were suffering. Marriage should be honoured by all and the marriage bed kept pure. Keep your lives free from the love of money and be content with what you have, because God has said: never will I leave you; never will I forsake you. So we say with confidence: the Lord is my helper; I will not be afraid. What can mere mortals do to me?
Remember your leaders, who spoke the word of God to you. Consider the outcome of their way of life and imitate their faith. Jesus Christ is the same yesterday and today and forever. Do not be carried away by all kinds of strange teachings. The Catechism identifies the unchanging nature of Christ as the ground of the Church's stability in doctrine: the same Jesus who taught the apostles and who instituted the sacraments is present today in the Eucharist and in the preaching of the Church, unchanged (CCC 1085).
We have an altar from which those who minister at the tabernacle have no right to eat. Jesus suffered outside the city gate to make the people holy through his own blood. Let us then go to him outside the camp, bearing the disgrace he bore. Through Jesus, therefore, let us continually offer to God a sacrifice of praise, the fruit of lips that openly profess his name. And do not forget to do good and to share with others, for with such sacrifices God is pleased. The God of peace, who through the blood of the eternal covenant brought back from the dead our Lord Jesus, that great Shepherd of the sheep, equip them with everything good for doing his will. To him be glory forever and ever.
Brothers and sisters, Jesus Christ is the same yesterday, today, and forever. Every doctrinal novelty that would change the substance of what he taught, every pastoral innovation that would alter what he instituted, runs against this verse. The faith handed on from the apostles is not an antiquarian preference. It is the living encounter with the one who does not change. Hold fast to the unchanging Christ and you hold fast to the eternal.
Lord Jesus, the same yesterday, today, and forever, equip us with everything good for doing your will. Through the blood of the eternal covenant, bring us back from every death into your service. To you be glory forever and ever. Through Christ our Lord. Amen.