I would say that the Arminian is a lost heretic who denies the law and gospel distinction

"'In the second place,' Gerhard continues, 'when the doctrine of the Gospel is not separated from the Law by definite boundary-lines, the blessings of Christ are co considerably obscured.' By ascribing to man some share in his own salvation, we rob Christ of all His glory. God has created us without our cooperation, and He wants to save us the same way. We are to thank Him for having created us with a hope of life everlasting. Even so He alone wants to save us. We to him who says that he must contribute something towards his own salvation! He deprives Christ of His entire merit. For Jesus is called the Savior, not a helper towards salvation, such as preachers are. Jesus has achieved our entire salvation. That is why we are so determined in our Predestinarian Controversy. For the basic element in the controversy has been that we insisted on keeping Law and Gospel separate, while our opponents mingle the one with the other. When they hear from us this statement: 'Out of pure mercy, God has elected us to the praise of the glory of His grace; God vindicates for Himself exclusively the glory of saving us,' etc., they say: 'That is a horrible doctrine! If that were true, God would be partial. No, He must have beheld something in men that prompted Him to elect this or that particular man. When He beheld something good in a person, He elected him.' If that were so, man would really be the principal cause of his salvation. In that case man could say, 'Thank God, I have done my share towards being saved.' However, when we shall have arrived in our heavenly fatherland, this is what we shall say: 'If I had had my own way, I should never have found salvation; and even supposing I had found it by myself, I should have lost it again. Thou, O God, didst come and draw me to Thy Word, partly by tribulation, partly by anguish of heart, partly by sickness, ect. All these things Thou hast used as a means to bring me into heaven, while I was always striving for perdition.'" - C.F.W. Walther, The Proper Distinction between Law and Gospel, pg. 40-41