Romans 6
"For sin shall not be master over you ..." (v14). We were all "slaves of sin." Christ freed us by conquering sin and death, and now we serve a different Master. In Paul's time, a servant "presented" himself to his master and awaited orders, signifying, "I'm at your service; I will carry out your plans" (v13). Paul urged believers to stop being instruments of evil; instead, "present yourselves to God" as His instruments, ready and willing to carry out His plans.
Being free is not passive; we are free in order to serve God, carrying out His plans in a broken world.