Every sinner will always resist as long as his heart and ears have not been circumcised. Regeneration is the Holy Spirit taking the resistance out of us and circumcising our heart and ears so that we want to believe. The verse does not refute irresistible grace but shows how essential irresistible grace is in true conversion. One more thing is important in this text. The resistance spoken of in these verses concerns the voice of the Holy Spirit speaking in the prophets.
Sinners can and do resist all of men's preaching and exhortations.
My son totally resisted all my entreaties with him for twenty two years. You may turn a deaf ear to the message when preached by men but when that message is applied to the conscience one on one by the Holy Spirit the resistance is removed. The internal work of the Holy Spirit in regeneration is quite different then the outward work of human agency. The former cannot be rejected but the later can and is rejected by many. The phrase irresistible grace turns some people off because they think of a steamroller rolling over a tube of toothpaste.