In spite of numerous difference between those who subscribe to Arminian theology and those who are Reformed in their understanding (of which I am one), the key to effective evangelism is a heart sold out to the Lord Jesus, a trust that God’s grace is capable of softening any heart, and not necessarily the theological bandwagon you happen to be riding.
In this article, Joe Thorn discusses how the common phrase “Preach like an Arminian, pray like a Calvinist” undermines both theological positions and the fact that love of Jesus is what feeds the fire in our bones to share the message of the Gospel–a love which is shared by the Calvinist and Arminian alike. Thorn specifically tackles the misconception that Calvinism leads to lacking evangelistic zeal and explains how, perhaps more than anything, understanding God’s sovereignty gives even more confidence to preach the Gospel with conviction and fervor.
If I say, “I will not mention him,
or speak any more in his name,”
there is in my heart as it were a burning fire
shut up in my bones,
and I am weary with holding it in,
and I cannot.
- Jeremiah 20:9
Article: Like a Man on Fire