According to my Oxford bible commentary the Jews thought of sex as a weakening. Pagan or libertine sex was viewed as a physical corruption. More of a perceived physical issue rather than spiritual.
Still don't think you can be Christian and willfully have sex out of marriage. If you go by Leviticus and a passage by Paul you can not be Christian and gay. Not that it matters to me what a gay person chooses, by scripture gay and Christian are mutually exclusive.
Christianity biblically based is also misogynist and pat5rirachal. Women should not be in leadership roles over men. So sayeth Paul.
Of course you can be a Christian and willfully have sex outside of marriage. Evidence of this can be seen in all the millions of people who are Christians who willfully have sex outside of marriage. They reconcile that with their faith by either completely ignoring the restrictions against this or deciding that those restrictions don't apply to their individual case because reasons.
They can also be gay or accepting of gays by not giving a shit about Leviticus. They also wear mismatched socks if they want, so it's not a huge deal to not give a shit about one more thing.