Is the clergy allowed to marry in your tradition and if so why, or why not?
As you know, in the Latin Rite, which is the rite of the majority of people in the Roman Catholic Church, priests are not allowed to marry. Celibacy is considered to be the most proper to the priestly ministry. It is in no way a depreciation of marriage, but it is the condition of greater freedom in the service of God. The law of celibacy is an ecclesiastical law, and could be abrogated if the Church so decided.
Celibacy was first required of all clergy by the First Lateran Council in 1123. The Second Vatican Council, in its decree on the priesthood, Presbyterorum Ordinis, published in 1965, continued to call for the practice of clerical celibacy (in paragraph 16) and the Code of Canon Law also requires it (canons 277 and 1037).
Roman Catholic theology speaks of celibacy particularly as a gift and as a way of loving. It is a gift from God that is intended to be shared; the celibate person lives for others. Celibate love is pursuit of holiness and an expression of love for God, and a sign of God's grace as a gift of oneself to others in ministry. Ultimately, celibacy is seen to be a call from God and a response to him on the part of those whom he has called to serve His people in ministry.
In the document Mulieris Dignitatem (no. 20), the late Pope John Paul II put it most succingtly when he said that we are celibate for the sake of the Kingdom. Basing this assertion on the evangelical values, he underscored that it is means by which one dedicates oneself exclusively to God and is a radical way of living the Gospel.