I'm essentially a grace alone through faith alone in Christ alone guy. And I believe that this is true just as much for revelation as it is for salvation.
Therefore Christ the Truth means Jesus is not just the one Way or one Life, but the one Truth of God. All truth - is in Jesus. This means all our thinking about God must begin with Him. Not some Christ-principle but Jesus of Nazareth. Not some divinized ideal but the actual Jesus of the Gospels.
When we do this we realize that Jesus is God-sized and God is Jesus-shaped. Thus we see the cruciformity of the Christian God. The Lamb is at the centre of the throne. God's perfection is in His mercy. His glory is His self-giving. This is unlike popular teaching on God acting with ultimate self-regard. His glory is NOT His self-centredness but His other-centredness. (Don't worry, I'm still a Trinitarian hedonist.)
Our God, most fundamentally, is trinity. He is One and Three. God's One-ness and Three-ness are not un-coordinated perspectives. Rather the Oneness of God simply is the communion of these concrete and particular Persons. To approach God's oneness in this way guards against many errors and brings many benefits. It also sheds light on how our own communities should be, whether that's marriage, family or church.
Of course this christocentric, trinitarian approach is not a New Testament novelty. Christ has always been the object of faith and hope for Old Testament believers. He is the Hope of the Ages - just study Exodus to see an example of it. Revelation has always been on a trinitarian dynamic. The Hebrew Scriptures give us a trinitarian witness on their own terms and in their own context.
From this it becomes obvious that there are no true understandings of God that are not Christ-centred, trinitarian revelations. Neither reason, nor creation, nor religion (be it biblical or unbiblical) can offer us stepping stones towards true knowledge. We either begin with the Christ, the Son of God or we don't begin at all.
This has important implications for apologetics and evangelism. For one thing, Christ alone and Grace alone means we must believe in Revelation alone. The direction of travel is always down from on high. The Gospel is not a good idea instead it is proclamation of things that have already taken place.
Yet this does not make us reductionistic. No, from Christ we can reason truly and understand the wealth of God's revelation in all the universe (even if we adopt views on creation at odds with the scientific majority). But actually all worldviews are religious - even the materialist ones. And all modes of enquiry follow a theological method: faith seeking understanding.
In all things we must realise that the God with Whom we deal is never an abstract deity but always the very concrete Jesus with His Father and Spirit - He is always and at all times irreducibly the God of the Gospel. And His being is unfolded and expressed precisely in the gospel economy.
Because He is love - a spreading goodness - His being is always towards our salvation. This is the way of the LORD. He determines to rescue us because He delights in us.
Thus the Father sends His Son to lay hold of our humanity in incarnation, to live our life through trial and temptation and to work out our righteousness in our place and on our behalf. Then He died our death in crucifixion. He was born again when He rose again as Head over creation and ascended to the Father's right hand in glory.
Humanity is not free to choose participation in this life. We contribute nothing to this salvation. Rather we are freed by the Son to enjoy His status. I am in Christ and Christ is in me. Thus we find ourselves as those already embraced by this triune God. We find ourselves participating in this divine nature - loved with the eternal love of the trinity. This is not a mush of groovy feelings but is enjoyed concretely as a cruciform life of cheek-turning.
In this we find our identity - not in personality types but in Jesus. We find our assurance - not in personal piety but in our perfect Priest. We find our encouragement - far above and beyond ourselves, in Christ who is our righteousness. Since this is so, sinning really isn't the worst thing - refusing His forgiveness is. We respond to sin by looking away from self to our Champion. This is not cheap grace, but true discipleship and in this we resist the devil. In such discipleship boasting is out and humility is in.
Such a gospel overflows in our hearts with singing and poetry and other creative things. But most of all with proclamation - we believe therefore we speak. Preaching is basically the heralding of our Champion's victory. You can listen to my own approach with these evangelistic talks or with sermon series such as Church in the Wilderness or Gospel alone.
There are ten things you should definitely avoid with preaching and there are ways of getting better at it - but we need to think carefully about them. Our proclamation is itself the Word of God. And there is incredible power in it. What we need is truly Christ-centred preaching and evangelism. And this is our task as we await the return of Jesus - not the moral/social/political reformation of society (or even ourselves), but the proclamation of King Jesus. And its point (its application if you will) is not moralism but always to look to Him.