There is really not much here that should be seen as cliched or biased, but here are some things that could possibly be changed.
- The only example of a cliche that I see is the phrase "this day and age." You might instead say something like "In today's world..." or even simply "Today, ..."
- The only thing here that could, to me, be seen as biased is the phrase "Christian youth." It implies, that youths who are "outside the church" are not Christian. So you might want to go with a more technically descriptive phrase. Depending on what, exactly, you mean, you might say "teens who attend church regularly" or "teens who are member of the ______ church..." You could then go on to compare them to "teens who do not attend church regularly" or "teens who are not members."
So your sentence might end up like this: "Today, teens who are members of XYZ Church are as likely to have premarital sex as those who are not members."
This day and age, Christian youth are having as much premarital sex as youth outside the church.
In order to rid writing of clichéd and biased language, you need to analyze and understand precisely what is being said. Since clichéd and biased language is what we hear on a regular basis, it may be harder than it sounds to determine the real meaning of such phrases.
"This day and age," (more commonly, "In this day and age"), is obviously a time reference to our current era. A few original ways--one might say authentic ways--of identifying the present chronological period might be:
In the early twenty-first century ...
In the first decade of this century ...
Between 2000 and 2012 ...
"Christian youth" might mean several things. It might mean young people raised by parents who hold Christian beliefs and take their families to church. It might mean youths who are themselves adherents of the Christian faith even though their families are not. It might mean teenagers who may have rejected the Christian faith themselves but whose families still attend services and practice Christianity. It might mean young people who were raised by Christian parents and who go with their families to church and who themselves have accepted the Christian faith as their own religious belief. You can see that this phrase has many variations in meaning, each of which radically changes the social group referred to.
Now, to rewrite the sentence without clichéd or biased language, apply this same kind of analysis to the rest of the sentence to uncover the authentic meaning throughout. Then rewrite the statement to assert specific, clear, definitive information. For example, based on options we have so far, you might write something like this:
In the first ten years of the twenty-first century, teenagers who attend Christian churches with their families but who have not embraced the Christian faith as their own ...