Every word has power.
Each word is important.
You are invited and challenged to take the following terms and define or describe them in less then 3 minutes.
As a start I suggest that the essential terms are:
Love
Faith
Hope
Mercy
Grace
Sovereignty
Free will
Body
Soul
Spirit
Justification
Sanctification
May I suggest that in order to effectively teach and train believers you need to be careful to define your terms. These days the same words are given very different definitions. Often these differences are minor but sometimes they are major. Besides the words listed here also be sure to clarify any words that seem to cause confusion in those who hear you. It may be wise to gradually build a glossary of terms that you use often in your teaching or preaching. Put these with your handouts, on your web site or otherwise make them available.
On a related note these concepts need to be taught
Enemies
World
Flesh
Devil
Systemic sins
Lust of the flesh
Lust of the eyes
Pride of life
Types of sins
Sins of commission
Sins of omission
Ways to spiritually clean up
Confess sins
To God privately
To persons as needed
Forgive persons
Ask for forgiveness
From persons as needed
Repent of sinful habits and attitudes
Common troubles (felt and submerged) that need biblical solutions
Guilt
Shame
Doubt
Unbelief
Worry
Fear
Resentment
Anger
Gluttony
Greed
Insecurity
Lust
Bitterness