Well, I think all good apologists would probably give you plenty of Scriptural background. I’m not a good apologist, but I’ll try to give you some info
One
Eph. 4:4-6
“…one body, and one Spirit, as you were also called to the one hope of your call; one Lord, one faith, one baptism; one God and Father of all, who is over all and through all and in all.”
Holy
Mt. 5:48
“So be perfect, just as your Heavenly Father is perfect.”
"Jn. 17:15-19
“I do not ask that you take them out of the world but that you keep them from the evil one. They do not belong to the world any more than I belong to the world. Consecrate them in the truth. Your word is truth. As you sent me into the world, so I sent them into the world. And I consecrate myself for them, so that they may also be consecrated in truth.”
1 Peter 2:4-9
"Come to him, a living stone, rejected by human beings but chosen and precious in the sight of God, and like living stones, let yourselves be built into a spiritual house to be a holy priesthood to offer spiritual sacrifices acceptable to God through Jesus Christ. For it says in scripture: “Behold I am laying a stone in Zion, a cornerstone, chosen and precious, and whoever believes in it shall not be put to shame. Therefore, its value is for you who have faith, but for those without faith; ‘The stone which the builders rejected has become the cornerstone,’ and ‘A stone that will make people stumble, and a rock that will make them fall.’ They stumble by disobeying the word as is their destiny. But you are ‘a chosen race, a royal priesthood, a holy nation, a people of his own so that you may announce the praises’ of him who called you out of darkness into his wonderful light.”
Catholic
Mt. 10:40 Whoever receives you, receives me, and whoever receives me receives the one who sent me."
Mt. 28:16-19
"The eleven disciples went to Galilee, to the mountain to which Jesus had ordered them. When they saw him, they worshiped, but they doubted. Then Jesus approached and said to them, ‘All power in heaven and on earth has been given to me. Go therefore, and make disciples of all nations, baptizing them in the name of the Father, and of the Son, and of the holy Spirit.’ "
Romans 16:25-26
“Now to him who can strengthen you, according to my gospel and the proclamation of Jesus Christ, according to the revelation of the mystery kept secret for long ages but now manifested through the prophetic writings and, according to the command of the eternal God, made known to all nations to bring about the obedience of faith, to the only wise God, through Jesus Christ be glory forever and ever. Amen.”
Apostolic
Mt. 16:18 “Thou art Peter and upon this rock I will build my Church, and the gates of Hades will not prevail against it.”
Mk 3:13-19
“He went up the mountain and summoned those whom he wanted and they came to him. He appointed twelve (whom he also named apostles) that they might be with him and he might send them forth to preach and to have authority to drive out demons: {he appointed the twelve} Simon, whom he named Peter; James, son of Zebedee, and John the brother of James, whom he named Boanerges, that is, sons of thunder; Andrew, Philip, Bartholomew, Matthew, Thomas, James the son of Alphaeus; Thaddeus, Simon the Cananean, and Judas Iscariot who betrayed him.”
Lk, 22:31-32
“Simon, Simon, behold Satan has demanded to sift all of you like wheat, but I have prayed that your own faith may not fail; and once you have turned back, you must strengthen your brothers.”
Too many more to type them all out…
Jn. 15:15-16
Jn. 20:21-23
Jn. 21:15-17
Acts 1:15-26
Eph 2:11-22
2 Tim 1:13-14
Ti 1:5-7
Ti 2:15
Now as to the importance of the four marks and why we hold them in such esteem?
Eph. 2:11-22
I hope these help you out a bit.
Blessings,
Gracie
