But doctrine itself gives no life at all. What gives life is that which the doctrine is about. For instance, what saves you is not a solid doctrine regarding how you were saved, but the actual work of Christ on the cross, from which any solid doctrine of salvation arises. If you get the doctrine right but don't put your life behind it, what good is the doctrine? The Reformers termed that frigida opinio , cold opinion, with which a person may agree with to the last detail but not have it touch them inside. It doesn't put them into action, fire up their passion, or change their attitude toward life. It is very much a dead letter.
Truth is not just something said or communicated or taught. Truth can also be in the doing, flowing out from a specific event in time and space. Truth can be discovered in what happens, and can be supported by other things that happen. Truth can be found not just in thought, but in deeds; not just in doctrine but in action, like the Spirit is in action. This is what happened at Pentecost -- the Spirit made an event of it, things happened, supported by fire and language miracles, and people took action. Through that 'happening' and those actions the truth of Christ was spread. We worship, we serve, we evangelize: we do the truth. When the Spirit is in us, so is Christ; Christ is truth, and so then collectively we embody something of that truth. This is one of the ways the Spirit relates life in Christ to our own lives.