Revelling is to engage and delight in worldly pleasures, participating in worldly, boisterous merry making or festivity. It is riotous and wild living.
You may have been a reveller in times past, but as a believer you are no longer to behave this way:
That he no longer should live the rest of his time in the flesh to the lusts of men, but to the will of God.
For the time past of our life may suffice us to have wrought the will the Gentiles, when we walked in lasciviousness...(I Peter 4:2-3)