The following is a comprehensive description of what Catholicism is--in as little a bite as possible, and with the aim to welcome you into our fold. Please don't be overwhelmed!
The Catholic Church is a community joined together by our profession of faith (grounded in Scripture and Tradition), by our celebration of the seven sacraments (visible signs instituted by Christ to give grace), and by our unity with the universal Church (in communion with the Pope, the bishop of Rome and successor of St Peter). Our faith is founded on belief in God the Holy Trinity—Father, Son, and Holy Spirit. We believe that for our salvation Jesus Christ, the eternal Son of God, was born of the Virgin Mary. He came as the fulfillment of the promises of the Old Testament. By his suffering, death, and resurrection he destroyed the lasting power of sin and manifested the love and mercy of God. As the Good Shepherd he seeks out the lost to reconcile them with the Father. By the sending of the Holy Spirit and rich gifts of grace, we are invited to enter into a new life. Jesus entrusted us with the gift of the Eucharist, his Body and Blood, which we celebrate at Mass (especially on Sunday and other holy days).
The Church is called “one, holy, catholic, and apostolic”—‘one’ because of her unity in faith, hope, and charity; ‘holy’ because of her Founder and the grace of God at work within her; ‘catholic’ because of the universality of her mission and members; and ‘apostolic’ because of her foundation on the apostles and her call to go forth in mission. The Church brings us into communion with people throughout the world, as well as connecting us with the great saints who have gone before us. However, the Church is also a home for sinners, supporting us as we seek to live our baptismal call. For this reason, the Church is both holy and always seeking conversion.
Founded on the twelve apostles, the Church is sent by Christ to continue his mission in the world. We are called to the two-fold commandment of charity: to love God with all our strength, and to love others as Christ has loved us. We draw near to God in the silence of personal prayer as well as in common prayer (most especially the celebration of the sacrament of the Eucharist—the Body and Blood of Christ—at Mass). We draw near to others especially through the corporal and spiritual works of mercy. All people are invited to become living members of the Body of Christ in a manifold richness of vocations: lay or as clergy; married, single, or consecrated. We seek to experience the joy of the Gospel and put our gifts at the service of others. By all these gifts of prayer and holiness, of charity and concern for those in need, the Church prepares for the fullness of the heavenly kingdom.