Contrapositives are sort of like calculus – you don’t use them much in the everyday activities of grocery shopping, taking care of babies, or cutting the grass. Engineers and logicians might use them in their work, but not your regular office worker, manager or even electricians.

So I was thrilled last week to have contrapositives show up in a sermon!  What are they, you say?  A term used in logic, it is a powerful tool to make an argument. The two logical statements below are contrapositives:

If A, then B.

If not B, then not A.

Contrapositive statements are either both true or both false; they are logically equivalent.

The series of sermons on 1 John are about evidences or signposts – assurances of salvation.  These are not causes, but results or indicators.  Several if-then statements are contained in chapter 5, verses 1-5:

If you believe that Jesus is the Christ, then you have been born of God.

If you love the Father, then you love whoever has been born of God.

If you love God and obey his commandments, then you love the children of God.

If you are born of God, then you have overcome the world.

If you believe that Jesus is the Son of God, then you have overcome the world.

Sometimes the contrapositive is easier to discern than the original:

If you are NOT born of God, then you do NOT believe that Jesus is the Christ.

If you are NOT born of God, then you do NOT love the Father.

If you do NOT love the children of God, then you do NOT love God or obey his commandments.

If you have NOT overcome the world, then you are NOT born of God.

If you have NOT overcome the world, then you do NOT believe that Jesus is the Son of God.

The sermon application was a refutation of the partly true statement that “No one ever really loves God or really loves his neighbor.”  The truth is that no one can love God or his neighbor perfectly.  But verse 3 of 1 John 5 says that these commandments of God are not burdensome, so they must be doable in some sense.  There must be room for a sanctifying, growing, overcoming-the-world love for God and neighbors that serves as a signpost / indicator of growth in belief and love for Jesus.