Asking others about Jesus' work on the cross.
As I talk more openly with people about salvation the + works crowd always chimes in. I'll spare the details but it's the typical fruit inspector stuff where they demand a Holy life to show gratitude towards Jesus.
The only blatant question I keep asking once debates turn into me constantly correcting verses (you know where they take a verse but intentionally leave out the previous/next verses) is
"Was Jesus' Work on the cross sufficient?"
Is this a bit too blunt?
Romans 5:8 But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us.