Thy word have I hid in mine heart, that I might not sin against thee. . .
Soldier, there is a battle raging around. You need to be taking in God's Word afresh each day. And, you must be memorizing each day.
So often children and new believers are taught to learn the primary verses of the faith. After a time, the practice of memorizing wanes.
Without memorizing (even if only a phrase at a time), there can be no meditating on the Word. Without meditating, the Word is not penetrating deeply or constantly.
There can be no power in prayer until the one who prays can agree with God. Agreeing with God requires a depth in His Word.
He is always fresh.
He is always new.
He is always infinite.
He is always revealing Himself.