If we approach the Doctrines of Grace (a/k/a Reformed doctrine) primarily just to make us appreciate our salvation more, then we will tend to tolerate Arminianism as just a stepping stone to Calvinism. Then, we will tend to view Arminianism as just a lesser appreciation of our salvation. Then, we will tend to view Arminianism, to use a material example, like salt rather than like leaven. With salt, we are only concerned if we add too much, and even then, there is no real damage. We can just brush it off. Is Arminianism like salt where there is no real harm if we add to it surrounding “good” teaching? NO! Can we just brush off Arminianism? NO! Or, is Arminianism like leaven that can corrupt the whole? YES! Arminianism is like leaven that can corrupt the whole.
We are called to “purity in doctrine”. Titus 2: 7. Scripture warns us against tolerating even a little false teaching. Such false teaching can corrupt the whole surrounding “good” teaching.
Scripture keeps coming back to the importance of truth. As the Scripture states, there are those who worship God in vain who teach or believe in doctrines based on the ideas of man. Matthew 15: 9. As Scripture states, those who worship God must worship in spirit and in truth. As Scripture states, the Spirit of truth guides the saved into all the truth. On the other hand, there are those who “did not receive the love of truth so as to be saved”. 2 Thessalonians 2: 10-13.
However, if we primarily approach the Doctrines of Grace as the truth that glorifies God, with only secondary concern as to whether or not it makes us appreciate our salvation more, then out of our concern for the truth, we will tend to oppose Arminianism as the opposite of truth or as the false “gospel”. We will also tend to focus on God and how the Doctrines of Grace glorify God, rather than focusing on us (man) and how the Doctrines of Grace are more gracious or more good to us than Arminianism. We will also tend to view Arminianism as leaven and see the urgency of purging our churches and households of it.