Paul wrote to Titus about the importance of sound doctrine and the ability to exhort and refute others with it. He saw that it is only by a healthy grasp of sound doctrine that we will live the lives God desires (Titus 1:1-2, 9).A systematic grasp of Christian doctrine (known as systematic theology) is therefore key if the Christian is to be able to critique ideas, answer questions, and think biblically in every situation. In this sense, doctrine is the DNA that determines true spiritual growth.
General
Can we be certain of God's truth?
The essentials and the Apostles' Creed
Gospel fundamentals [external]
Overview 1: God, Bible, Man [external]
Overview 2 : Jesus, Spirit, Salvation [external]
Brief answers to tough questions
Specific
The inspiration of the bible [external]
The trinity [external]
Sin and death
About hell
Providence and predestination
The person of Christ
The work of Christ [external]
The cross of Christ [external]
What is repentance?
How God speaks today
Being a Christian
What it is to be a Christian
The Christian life
Why I am a Christian [coming]