Who was in Christ according to Paul's statement that Les explains?
According to Paul's statement, the whole triune God, with all His power, was in Christ. God was in Christ reconciling the world unto Himself, not imputing their trespasses unto them, and has committed unto us the word of reconciliation. This is the ministry of reconciliation.
Les explains that Paul's statement in verse 19 says the whole triune God, with all His power, was in Christ, reconciling the world unto Himself and not imputing their trespasses unto them. God has done everything needed to set a person free and reconcile them to Himself, and He has given believers the ministry of reconciliation. Les also explains that believers are left here as ambassadors—representatives of a government in a strange land—ready to take the opportunity to tell those wrapped in Satan's web that God has done everything needed to set them free.