احسن الله اليكم Is it wajib on a man to listen his step-father and obey him in what does not have a sin in it؟ and to treat him and respect him as he would be to his father

Ustadh AbdulAziz al-Haqqan
Why not? We treat elders with respect even if they are not family so it makes more sense to do so for family and he should as well treat you as his son and loves for you what he loves for his children.