Shabbat shalom kol beit Yisra'el!
I have been asked why we as Messianic Evangelicals observe a Bar Mitzvah when this term is not mentioned in the Bible and also what form do we use. First of all I have to say that we follow neither Jewish nor Messianic Jewish ceremonial customs which have evolved over the centuries, but let's begin with a brief historical overview.
Before there was any 'Bar (or Bat) Mitzvah' it was clearly understood from the Torah that a man became of age when he was 20 years old, what we call the 'age of majority'. At that age he became eligible for both military service and taxation. In other words, this was the age at which he became a 'man' and a father was officially relieved of any responsibilities for him. This remains true in the New Covenant as Yahweh has not changed the age of majority even if secular governments have, the most typical age being 18 today. As far as Messianic Evangelicals are concerned, a boy does not become a man until he is 20.
In Talmudic times the age of majority was arbitrarily changed from 20 to 13 but no celebration marked this occasion. The father simply praised God for relieving him of his responsibility for his son's conduct. By the 16th and 17th centuries AD amongst the Ashkenazi Bar Mitzvah became interwoven with various ceremonies such as the wearing of phylacteries or tefilin (which were invented by the Pharisees) and the right of Jewish boys to participate in various rituals such as reading Torah from the bimah or pulpit and to recite various liturgical blessings. Most of the customs surrounding this Talmudic Bar Mitzvah were evolved in Poland. By contrast, the Sephardi Jews allow their boys to put on tefilin when they are 12 which constitutes a major ritual, as is also true of Moroccan Jews.
Messianic Evangelicals follow none of these extra-biblical customs. We maintain that a man comes of age at 20, as was acknowledged anciently in biblical times. However, just as we believe a child is old enough to be baptised by the time he attains 8 years (though this is not fixed - it will be a function of his or her spirituality and ability to both comprehend and accept the Apostles Creed as well as having been genuinely born-again), so we believe that by the time he/she attains the age of 12 he/she is usually old enough to become a Son (or Daughter) of Covenant if he/she has been properly taught, and is spiritually mature enough to understand the 10 Commandments and basic Torah be be accountable before Yahweh for obeying them. This we call Bar Mitzvah (for boys) and Bat Mitzvah for girls and constitutes the next stage (after baptism) of spiritual maturation. Again, 12 is only a minimum age or guideline. The nearest equivalent to Bar/Mat Mitzvah would be the Christian tradition of Confirmation which for Messianic Evangelicals converge as one since we permit those who have become so confirmed or 'christmed' (as we also call it) to partake of the Lord's Supper.
For boys the ceremony is short and simple involving a covenant to obey Torah and to wear Tzitzit or Tassels, as is required by Yahweh's Torah, for the rest of his life, and the laying of hands by his father or guardian. The covenant also confirms for the boy his father's authority over him until he becomes a man at 20. For girls a similar covenant is entered into with the agreement to wear a headcovering for the rest of her life, confirming her father's authority over her until she is married and that authority is finally transferred to her husband. (If the father is an unbeliever or dead, this authority can be conferred on a male guardian).
One who has become Bar Mitzvah has, by implication, not only been born again but also received, or been filled by, the Baptism of the Ruach (Spirit). We expect there to be some sort of evidence of this anointing before we administer this covenent and confer tzitzit or headcoverings.
As Shavu'ot is the time believers renew their Messianic Torah Betrothal Covenant with Yah'shua (Jesus), so Shavu'ot is also a popular time for boys and girls who have attained the age of 12 or above, as well adult converts, to enter Bar Mitzavh covenants for the first time, in the same way that Yom haBikkurim is the preferred time for 8 year olds and adult converts to enter baptismal covenants. However, baptism and Bar Mitzvah/Chrism can take place at any time of the year. We also allow Bar Mitzvahed boys and girls to start training as Sub-Deacons and Sub-Deaconesses if they are called and accept their calling though they must wait until they are adults before ordination.
This Messianic New Covenant Bar/Bat Mitzvah is rather different from the ceremony and meaning of the pratice of the same name performed by Jews and Messianic Jews, being also known by us as Confirmation and Chrism, the latter term being common in the sub-apostolic era. Bar/Bat Mitzvah is therefore the Shavu'ot Stage or 'Stage 2' of the three-part coming of age of children physically and spiritually as well as that of adult converts spiritually, and reflects the divine tavnith of Messianic Israelite life.
If you have been baptised but never confirmed, prayerfully consider taking the next step into becoming a Son or Daughter of Covenant. It is what makes an Evangelical into a Messianic!