“So you must live as God’s obedient children. Don’t slip back into your old ways of living to satisfy your own desires. You didn’t know any better then. But now you must be holy in everything you do, just as God who chose you is holy.”
God is always offering us a clean slate and an opportunity at a new start. He doesn't need a specific time of year for us to make a decision to completely follow Him. He is always there, always waiting for us.