As Paul comes to the end of this letter, emotionally difficult to write and difficult to read, he asks the church in Corinth to check their spiritual health. Until this point he had focussed on their behaviour as an expression of what they believe, now he is direct. "Are you in the faith?" He had been honest with them about his own lifestyle of trust and sacrifice for the sake of Christ (2 Corinthians 11:7-12), so now, what about them? He does not ask if they believe something about God or Jesus but if they are actively seeking to live inside the protection of the blood of Christ, within His love and in obedience to His will.

They had been preoccupied by personalities and passions: who to follow, how to indulge their pagan lifestyle within the church and how to please themselves (2 Corinthians 12:20). That was not a good advertisement for the body of Christ. So Paul's question goes deeper – "Is Jesus Christ in you?" It was a very searching challenge. Everybody who has God's Spirit knows that Christ is in them, and those who do not have the Spirit have no confidence that they are in Christ or Christ is in them (Romans 8:9).

Of course the big test is not in our feelings, important as they are, but in our obedience ... or how do we deal with disobedience. Nobody is fully obedient but those who are in Christ will find their own disobedience repugnant: they will cry out for mercy and seek to make amends for their sin (1 John 1:8-10). The true Christian (Christ-in person) will strive to obey and quickly repent of disobedience. They will not be driven by what they want but what the Lord wants, and will know the shame of sin – their only remedy will be the cross of Christ and His grace in restoring those who are repentant (Ephesians 1:13).

The test is not so much how high can you jump in doing right, but what do you do after you have fallen down. For true believers, even though they know their sin has offended Jesus, they also know that He is the only person they can run to for mercy and forgiveness (2 Corinthians 7:10-11). Those who are not in Christ will try to bluff their way through, or pretend there is no problem or seek some alternative diversion or therapy; instinctively they will run away from the Lord. "Are you in the faith?" is a necessary question to everybody who goes to church, because not all are. www.crosscheck.org.uk will help you to find out if you are in Jesus Christ, or help you to help others. It is the biggest question you will every answer in this life and Jesus will ask it on the Last Day. If you are not, you can be – however bad your sin – let the CrossCheck video and verses help you be sure.