Are Christians under the law and rules and regulations?
No. Believers are not under a mandate of law, nor are they under rules and regulations. Instead, they respond as the Holy Spirit leads them in their life of service, testimony, and everything, presenting their bodies as wholly acceptable to God.
Les explains that Paul's plea is for believers to present their bodies, not their souls, as wholly acceptable to God, which is their reasonable, logical, practical service. He emphasizes that they are not under a mandate of law or rules and regulations; rather, they respond as the Holy Spirit leads in service, testimony, and everything. Les also uses the jello mold analogy: once poured into a mold and set, it takes that shape. Paul therefore says, do not be molded according to this old world, which is under the control of the wicked one, but be transformed. This is not forced; it is of our own free will.
I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.