The Pentecostals and the Charismatic group think that the most distinguished characteristic of the baptism in the Holy Spirit, of this descent and fullness of the Holy Spirit is to speak with tongues. Speaking in tongues, in their opinion, is the first sign that a person is filled with the Holy Spirit. That is why, in joining a new member to their group, the Pentecostals and the Charismatic group strive to make him or her speak with tongues so as to resemble the Apostles on the Day of Pentecost.