Biblical doctrine is made practical when seen in the context of spiritual warfare

When you seek what is practical - when you are practical - with biblical doctrine it comes down to seeing it in the context of spiritual warfare.

Example: classical covenant theology, the massive structure of it, three covenants, from eternity to eternity, can seem to people as alot of esoteric or arcane theological intellectualizing, but when you understand it and then you see it in the practical context of spiritual warfare it itself becomes practical and something that effects you in real time in a very real way.

Spiritual warfare is about kingdoms. The Kingdom of Satan and the Kingdom of God. Competing claims to souls, competing jurisdictions and laws and status and power and so on. When you are regenerated by the Word and the Spirit you are freed from the Kingdom of Satan and become a citizen of - given legal status in - the Kingdom of God. You have to realize this and assert this boldly because in the spiritual warfare that follows regeneration the devil and his ministers and followers and duped slaves will challenge your status and seek to fool you about your status as much as they can get away with. But when you know of the Covenant of Redemption and the legal foundation of your being a subject of the Kingdom of God, and what it brings you which is everything God has, you being an heir of the Living God of all Creation (think of - on a smaller scale - the biblical analogy of how the apostle Paul benefited legally from his being recognized as a Roman citizen) you are acting in your spiritual battles with knowledge and understanding of who you are and what you are, and this makes you more formidable a soldier of Christ in Christ's army.

As Paul had standing upon the laws of Rome and thus protection from Rome (using that smaller scale example) you as an effectually called, regenerated, justified believer in the Lord Jesus Christ stand upon the eternal Pactum Salutis and thus draw real protection from that Eternal Covenant, and this also lets you know who you are and what is expected of you and what powers you have derived from it. It gives you a real sense of why and how you are to glorify God.