Actually, if we could shed the baggage of what's meant by
@Rufus and begin looking at this rhetoric with a little effort applied to semantics, logic, other Scripture, and some mutual understanding and grace to work, I could work with it.
"By you're [your] freewill choice [to believe God] you are in Christ Jesus"
- 1Cor1:30 clearly identifies God as the origin, the source, the cause for believers being in Christ Jesus. No matter how much poor argumentation is thrown against us, I'm comfortable some of us fully understand and believe this foundational truth - from God we are in Christ Jesus.
- And from God is required that we choose to believe Him to be entered into Christ Jesus by Him. So, in this sense of God requiring that we choose to believe Him, it could be said that we do enter into Christ in part by choice as is God's will and design and actually, His command and requirement.
- Following @Rufus method of FTFY, I've changed His rhetorical statement to reflect God's requirement to believe which I believe we do make the choice to do just as He requires that we do. I just wouldn't change 1Cor1:30 and would find other Scripture to back this up which I'm not going to do now.