I Corinthians 1:30 says of the Father, “But of him are ye in Christ Jesus…” Are we in Christ because of a decision we made? No. It’s because of election.
If someone says this text applies to all men, then the logical conclusion one must make is that some will burn forever in the lake of fire while “in Christ Jesus”. That is a monstrosity. An opponent of the truth may further say that those who will suffer eternal torment somehow got out of Christ after being put in by the Father. If that be true, I would like to see the verse that tells how they got out after being put in.
The truth is, those in Christ are preserved there, kept by the power of God (Romans 8:35-39, Jude 1:1). In John 14:20, Jesus said he is in the Father. So, we are in Christ, and he is in the Father. How secure is our eternal life? Colossians 3:3 says, “your life is hid with Christ in God.” Sounds like a secure package to me.
Yes, it is possible to go astray to love and serve the things of this world more than God, but for that we will experience torment and problems in this life. As far as the world which is to come, the eternal life of the elect is as sure as if they were all already in Heaven. The gospel and our realization that Jesus is our Savior brings us joy and happiness in this life, but it does not bring eternal life. Only by Christ’s pure blood are we cleansed and made fit to be in God’s presence forever.