Should all sermons be John 3:16?
It is a common belief that whatever text of Scripture is being taught in a sermon, the pastor should find the quickest path to Jesus and then preach how Jesus died for our sins and how we can be saved. But are we ignoring an infinite number of incredibly valuable lessons for our daily lives if we boil every sermon down to John 3:16 and how we can move from condemned to redeemed? What happens after we are redeemed?
If you read the New Testament epistles, there is a huge amount of basic, practical, day-to-day instruction on how to live as a Christian and glorify God, not to mention warnings written to Christians about the dangers of sin. There are numerous warnings in both the Old and New Testaments for parents (especially fathers) to discipline their children, and at the same time to balance that discipline with love and affection.
There is a reason the Apostle Paul wrote this with the inspiration of the Holy Spirit:
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works. -- II Timothy 3:16-17
The Bible, in both the Old and New Testaments, provides us with an incredible treasure of lessons for us to learn, heroes for us to imitate, and villains to teach us how not to behave. All of this is done to point us to the Gospel, to be certain, and that should always be preached. But it would be a disservice to the Body of Christ not to spend a great deal of time on those lessons and preach exclusively on Christ's substitutionary atonement.
Obviously, the Gospel is the critical point in the life of any believer, and it is critical for us to be reminded that Jesus died for us so we can be free from the bondage of sin. Evangelism is a core duty of every Christian, including (and especially) preachers. But for a Believer, accepting Christ as our Lord and Savior is the starting point, not the end point. Sanctification continues throughout our entire life, and our pastors need to help us learn how to obey God, kill our sin, love our neighbors and be salt and light.