Complex sentence: His arms are heavily lacerated by what appears to be whip marks, he weakly raises his right hand to display to the viewer the deep wound to his side, where, according to scripture, he was pierced by a lance while crucified on the cross.
Split into simpler sentences: His arms are heavily lacerated by what appears to be whip marks. Christ weakly raises his right hand to show the viewer the deep wound to his side, where, according to scripture, he was pierced by a lance while crucified on the cross.