Romanos 9:21

‘Or has the potter not a right over the clay, from the same lump to make one part a vessel to honour, and another to dishonour?'

He now illustrates his position in terms of a potter who has a lump of clay and can use it both to make an ‘honourable' vessel and to make a ‘dishonourable' one. Which he makes is solely up to the potter's discretion. So a potter may take his piece of clay, and set aside one part to produce an ornamental vase, and another part to produce a crude chamber pot. No one will question his right to do so. The idea therefore is that God has the same right to do what He will with what He has created. Applying this to his earlier argument Isaac and Jacob were honourable vessels. Their brothers were dishonourable vessels.

It is a quite false position to argue that Paul is likening ‘feeling people' to mere lumps of clay, anymore than to argue that he is likening a humble potter to God. That is not his point. He is using an illustration, and his emphasis is on the fact that like the potter God can determine to do what He will.