Some definitions of "Church" in the New Testament:
• 1 Corinthians 12:27: "Now you are Christ's body, and individually parts of it."
• Colossians 1:18: "He is the head of the body, the church."
• Ephesians 1:22: "And he put all things beneath his feet and gave him as head over all things to the church, which is his body."
• A definition from the Catechism of the Catholic Church, 777-780: The word "Church" means convocation.
It designates the assembly of those whom God's Word convokes (i.e., gathers together) to form the People of God…the Body of Christ.
The Church is both the means and the goal of God's plan; the Church has been manifested as the mystery of salvation by the outpouring of the Holy Spirit.
She will be perfected in the glory of heaven as the assembly of all the redeemed of the earth (Revelation 14:4).
The Church is both visible and spiritual, a hierarchical society and the Mystical Body of Christ.
She is one, yet formed of two components, human and divine. That is her mystery (Ephesians 5:32), which only faith can accept.
Is the Church, the People of God, the perfect and sinless kingdom of heaven on earth?
Yes and No.
Yes, the Catechism of the Catholic Church (823): "The Church…is held, as a matter of faith, to be unfailingly holy. This is because Christ, the Son of God, who with the Father and the Spirit is hailed as 'alone holy,' loved the Church as his Bride, giving himself up for her so as to sanctify her" (Ephesians 5:25-27).
No, the Church is holy but it is made up of sinners. All members of the Church are sinners, and its ministers are no exception. The Church has survived many trying situations in 2,000 years. Despite all of our human weaknesses, remember what Jesus said about the Church, "The gates of the netherworld shall not prevail against it" (Matthew 16:18). It never has and it never will.
So let us live with love for everyone, for all are made in the image and likeness of God (Genesis 1:26), and witness to the joy of being a member of his Church, the Body of Christ; supporting those who believe and bringing hope to those who don't know the Father, Son and Holy Spirit.