In this model Christ did PART of salvation for ALL of mankind.
Some believe that when Jesus died on the cross he paid for the sins of ALL of mankind. Furthermore, he only did PART of the work so that individuals must meet an additional condition to be saved.
For example, consider that Mother Teresa and Hitler are both within the PART of mankind to whom Jesus offered forgiveness, because in this model Jesus died for ALL mankind. However, if Mother Teresa does not meet the particular condition required for salvation, because she has sinned even once, she cannot be saved from eternal damnation in the end. However, if Hitler meets the particular condition required for salvation, typically suggested to be man's free will acceptance of Jesus, even though he sinned terribly in many other ways, then he will be saved from eternal damnation to eternal life in the end. Of course, some might say that the condition is simply to be "good enough." Yet how would you measure that with confidence?
Thankfully, this view agrees with I John 2:1-2. However, it disagrees with Ephesians 2:8-9. Classic Arminianism fits the description of the PART-for-ALL salvation model.
Another verse that has been used to suggest the Arminian view is Galatians 3:2 (WEB). This verse could be understood to imply that our act or choice of faith invites the work of the Spirit. "I just want to learn this from you: Did you receive the Spirit by the works of the law, or by hearing of faith?"