The act of professing or claiming; open declaration; public avowal or acknowledgment; as, professions of friendship; a profession of faith.

That which one professed; a declaration; an avowal; a claim; as, his professions are insincere.

an open avowal (true or false) of some belief or opinion; "a profession of disagreement"

affirmation of acceptance of some religion or faith; "a profession of Christianity"

Profession, in a religious sense, is a public avowal of faith according to a traditional formula. In this sense, a "professing Christian" is one who publicly claims to be following and supporting the Christian faith, usually according to one of the formal creeds, such as the Apostles' Creed, the Nicene creed, or specific denominational confessions such as the Lutheran Augsburg confession or the Reformed Westminster Confession of Faith.