Ephesians 6:5-9 NABRE
Slaves, be obedient to your human masters with fear and trembling, in sincerity of heart, as to Christ, not only when being watched, as currying favour, but as slaves of Christ, doing the will of God from the heart, willingly serving the Lord and not human beings, knowing that each will be requited from the Lord for whatever good he does, whether he is slave or free. Masters, act in the same way toward them, and stop bullying, knowing that both they and you have a Master in heaven and that with him there is no partiality
How does this text from Paul's letter to the Ephesians show that the NT is anti slavery?
If Christianity is only based on the NT then why was it necessary to prove that Jesus was descended from the line of David?
Jeremiah 23:5
“ Behold, the days are coming,” says the LORD,
“ That I will raise to David a Branch of righteousness;
A King shall reign and prosper,
And execute judgment and righteousness in the earth.
Matthew 1:20-22
But while he thought about these things, behold, an angel of the Lord appeared to him in a dream, saying, "Joseph, son of David, do not be afraid to take to you Mary your wife, for that which is conceived in her is of the Holy Spirit. And she will bring forth a Son, and you shall call His name JESUS, for He will save His people from their sins." So all this was done that it might be fulfilled which was spoken by the Lord through the prophet.
There are many such links back to the OT.