I agree with Dan58. I backslid for about 10 years -- didn't do anything horrendous during those 10 years, but I wasn't going to church, didn't have any Christian fellowship, most importantly, lost my connection with God. Fortunately, God didn't lose His connection with me, watched over me those 10 years.
When I came back to Him, had a spiritual re-birth (again), I didn't feel the need to be re-baptized, and the pastors at my new church didn't think it was necessary.