The phrase "affirm belief" is correct and usable in written English.
It can be used when expressing or confirming one's conviction or faith in something.
Example: "During the discussion, she took a moment to affirm her belief in the importance of education for all."
Alternatives: "confirm faith" or "assert conviction".
For these reasons, one would be hard pressed to find very many theists (as opposed to deists) who do not also affirm belief in an afterlife.
All religions, except highly rational versions of any religion, affirm belief in the miraculous; and most religions bulge with miraculous tales.
Even among those who are current "temple recommend" holders (a subgroup of active Mormons who pass an interview with an ecclesiastical leader in which the individual is required to affirm belief in core Mormon doctrines, about 52% of all Mormons), 4% expressed at least a degree of doubt in LDS church teachings.
The Jesuits affirmed "belief in a God who is justice because he is love".
The Road affirms belief in the tender pricelessness of the here and now.
Our findings indicate high levels of subscription to negative beliefs about condoms, with two out of three respondents affirming belief in at least one negative condom rumor.
It focuses on "the three Abrahamic religions" — Judaism, Christianity and Islam — each of which takes as a forebear an "itinerant herdsman" of the Middle East, Abraham, who affirmed belief in a single God.
Al-Ashʿarī's harmonization also produced a simple creed, which expressed faith in God, his angels, and his books, and affirmed belief in Muhammad as God's last messenger and in the reality of death, physical resurrection, the Last Judgment, and heaven and hell.
All students must sign a "Statement of Faith" before they arrive, affirming belief in what the college considers core Christian doctrines.
And Francis's remarks don't constitute any change in doctrine: In 2012, the Vatican's chief astronomer affirmed belief in the Big Bang and evolution was compatible with the Catholic faith.
Pay attention to the ways that you repeatedly affirm your belief by creating, promoting, and allowing experiences that are consistent with that belief.
