The father of G12, César Castellanos, claims that the movement sprang from a series of amazing revelations he received directly from God. As he explains it, in 1982, he resigned as pastor of a small, struggling church in his native Colombia after he grew weary of losing his members and having to “chase after the people begging them, ‘Don’t leave, you are needed and you are important to us.’ I said, ‘Lord is this what you called me for, to beg people to come back to You? I don’t want this! If this is what shepherding is then this is not what I want.’ He resolved not to return to the pastorate until God confirmed the more specific purpose of my call.”
Four months later, while vacationing on the Atlantic coast, Castellanos heard the Lord command him to “Dream of a very big church because dreams are the language of My spirit!” That day, God promised that “The church that you will shepherd will be as numerous as the stars in the sky and the sand on the seashore. It will be so big that it will be countless.” (According to Castellanos, “The Bible says that we were created in His image and likeness,” thus “we are capable of dreaming and planning our future just as God does.” ) The official G12 web site claims that This revelation cut Church History in Colombia in half and also in the rest of the world. 
Emboldened by his seaside revelation, on March 19, 1983 Castellanos founded a new church the Mision Carismatica Internacional (MCI) with just eight people in his living room. In time, Castellanos saw the congregation mushroom to 3,000 members yet he still longed to see it grow.
In 1986, Castellanos traveled to the megachurch of pastor David Yonggi Cho in Seoul, Korea in hopes of implementing a successful cell-church strategy in Bogota. But even using Cho’s techniques, after five years the Mision Carismatica had only 70 cell groups — far fewer than Castellanos desired. So he resolved to call upon God again to learn how to accelerate his church’s growth. In 1991, his prayer was answered when he received the “extraordinary revelation of the Principle of Twelve.” He explains that “God removed the veil from my mind and I received the model that is now revolutionizing church growth. God validated the model by reminding me [of] the way Jesus had worked with His twelve disciples.” 
There’s no question the methods Castellanos uses produce results. According to the Wall Street Journal, the membership of his Bogota-based congregation has “increased exponentially and has now reached around 300,000 meeting at various satellite churches” throughout Colombia.  In fact, the Mision Carismatica claims “50,000 cell groups in Bogota” alone  and is considered one of the ten largest churches in the world.  Together with his wife, Pastora Claudia, Castellanos vigorously promotes his G12 vision across the Americas, Europe, Africa, and Asia in a dozen or more languages. (As of July 2006, more than 380 churches in North America had registered to use the G12 system. )
César Castellanos guarantees his cell vision will revolutionize the church in our time:
We have entered a new millennium and the Church must continue fulfilling the Great Commission with greater zeal. The harvest in this century will be so great that only those churches that adopt the cellular vision will reap its benefits. There is no alternative. The cellular church is the Twenty-first Century Church. 
Castellanos also warns that pastors who do not accept his cellular vision are not fulfilling the Great Commission:
Every leader must know that there is a window of grace in which we must carry out the Great Commission. This task is possible through the cellular vision. 
It can be said that a pastor who does not embrace cellular growth is stunting the spread of the gospel. 
To be able to move according to the demands of the 21st century, every pastor must change his traditional way of thinking and enter into the cellular vision; if a pastor changes, the miracle is already done, because this way he can influence his entire community. 
Implementing G12 can bring drastic changes, virtually wiping out existing church structures and programs. Still, Castellanos virtually guarantees that any church that abandons its traditional approach and fully adopts the G12 vision will grow, declaring: “The model of twelve is a very jealous one; either you take it in its entirety, or you don’t; there is no middle ground.”  God, he says, has revealed that only his “cellular structure” can accommodate the multitudes who will be saved:
We have received the Word in the sense that in the coming years there will be people hungry to receive the message of salvation; millions and millions will run through the streets demonstrating their desire to know of Christ, and the only structure that can permit [us] to be prepared for this is the cellular structure. 
Castellanos underscores the special role he plays in the history of Christianity. For example, in his book Dream and You Will Win the World, he reproduces portions of a 1997 prophecy given to him through latter-day “apostles” Bill Hamon and Cindy Jacobs:
And the Lord says, ‘Son, I have sent you for the healing of the United States. My son, I could have found someone else, but I am asking you to do this. Only you! I anoint you as I did Joseph when I sent him to Egypt to heal the nation. 
From now on you will talk with apostolic authority and fresh anointing. Nations will rise and collapse with the prophetic word that will come out of your mouth. 
Castellanos attempts to justify his distinctive “government of twelve” biblically by stating that “The number twelve always appears in the Bible as a symbol of administrative plenitude and spiritual authority relative to organizing people.”  Castellanos notes God established twelve patriarchs (Genesis 35:2226), there were twelve stones in the high priest’s breastplate (Exodus 28:29), and “With twelve disciples Jesus fed the multitudes, (Mark 6:3544) and with those twelve God established His kingdom on earth.” Perhaps most significantly, he adds, “Jesus selected twelve men in whom He reproduced His character, and they became His representatives in the world.” 
G12 training materials are saturated with language reminiscent of sales motivation, in which the faithful are repeatedly exhorted to become “winners” and “leaders” and strive to achieve “victory” and “success”. Pastors who travel to Bogota to learn the G12 strategy at the source are offered a comprehensive training package, and they are encouraged to purchase all of Castellanos’s books so they can fully implement his strategy in their churches. Churches are also encouraged to join the official “G12Net” in order to work with MCI and use its approved methods and materials. As one official G12 web site explains:
Pastors César and Claudia Castellanos are regularly receiving fresh revelation to bless and equip churches. This refreshing, rhema word needs to be available to pastors and leaders in the vision. The Castellanos are, in reality operating in an apostolic role. They are the Apostles of the vision, like John Wesley was the Apostle of the Methodist Holiness movement. The G12 Network is the apostolic platform for the Castellanos to pastor the vision worldwide. The G12 vision runs on the fuel of Holy Spirit revelation. The more revelation a Pastor or leader has about the vision, the more success he or she will achieve in the vision. 
Upon returning to his church, a pastor is to train twelve people from his congregation in the G12 strategy; this group will be “the pastor’s twelve.” Next, each one of these twelve must go and do likewise by choosing twelve disciples of their own who will, in turn, seek twelve more disciples via home cell groups, giving preference to “those who are most successful in producing fruit ”  Some observers note that the resulting pyramid structure resembles well-known multi-level marketing models (or worse, classic Ponzi* schemes).
Broadly speaking, the G12 strategy employs a four-step method called the “Ladder of Success:” winning, consolidating, discipling, and sending. At its most basic level, the initial twelve chosen by the pastor should seek a host who will open his house or office to start a cell group. A leader coordinates the group, assisted by a “Timothy” who is responsible for opening new cells once the initial group exceeds twelve participants.  A cell may begin with six people. At each gathering, the strategy of the vacant chair is used, in which participants commit to inviting someone so the seat will be occupied by a new person at the next meeting. Castellanos advises: “The cell should aim to win at least one new believer every week.” 
Unlike traditional cell-church models, the G12 system demands each cell leader and his or her assistants set ambitious “growth goals.” For example, the target might be set on a weekly basis (in which a new believer must be won every week), or a monthly basis (in which the cell leader is expected to open one new group per month). Thus, after twelve months, each leader would have at least 12 cells; and after 24 months, there would be an average of 144 cell groups.
In the G12 “cellular vision,” discipleship is the key to church development. In this system, before a Christian can be considered a disciple, he or she should be directing at least one cell group. Otherwise, he cannot be part of someone else’s “twelve,” and should submit himself to the authority of the leader who chose him. When this disciple has his own twelve, these will also submit themselves to him.
Not surprisingly, Christians across Latin America have testified that the G12 multiplication process is characterized by relentless pressure to proselytize and submit. (As the sign outside one G12 church in El Salvador warns, “The cell that doesn’t evangelize [will] fossilize.“)
Each leader has three main responsibilities. The first is to meet once a week with his or her own leader (to whose group of twelve he or she belongs); second, to direct his or her own weekly cell group; and third, to meet with his or her own twelve disciples once a week. Once a leader has his or her twelve, he or she will have to help his or her twelve to each select their own twelve, until the number of people under him or her reach 144 subordinates (with the leader at the top of the pyramid). At that point, the leader no longer directs his or her own cell group, but continues to supervise his or her own twelve to assure that all is running correctly.
The following steps can vary from country to country and from church to church. Typically, the nonbeliever who begins to attend a cell group and receives Christ as Savior will attend church on Sunday and respond again to the altar call. The three steps that follow — “Pre-Encounter,” “Encounter,” and “Post-Encounter” — are called the “Consolidation Process” and should begin “immediately after the new believer has made his decision for Christ.”  To prepare for the Encounter, the new convert should participate in a series of four weekly, one-hour studies:
Next the convert is strongly encouraged to participate in a weekend Encounter and little wonder. Castellanos declares, “We have proved that an Encounter is equivalent to a full year of church attendance.” 
*Ponzi schemes are an investment swindle in which high profits are promised from fictitious sources and early investors are paid off with funds raised from later ones. (The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.)