The Gospel Mystery of Sanctification: Growing in Holiness by Living in Union with Christ by Walter Marshall is a treasure trove of biblical truth on how Christians grow in obedience by the power of the gospel, not by their own strength. This little known book was originally published in 1692. Bruce H. McRae updated the book into modern English in 2005. You can read a brief bio of Marshall here.
I highly recommend it to any Christian seeking to grow in holiness (all of us!). Here’s Marshall on the elements of true faith…
When you believe the truth of the gospel, you receive the truth in which the knowledge of Christ is delivered to you. When you believe in Christ, you receive Christ himself, and his salvation, which are spoken of in the truth of the gospel. It is like this; It is one act when you receive a cup filled with wine, and it is another act to drink the wine in the cup. Those are two separate actions, but if you are going to drink wine, you must do both- you must receive the cup, and you must drink the wine.
This is what true saving faith is like. You must have both of these elements. First, you must wholeheartedly believe the truth of the gospel, and love that truth. Second, you must desire Christ and his salvation above everything else, and wholeheartedly receive him. You have to have a “spiritual appetite,” which leads you to eat and drink Christ, the bread and wine of life- in the same way that a physical appetite leads you to eat real bread and drink real wine. Spiritually speaking, faith means that you feed on Christ, in the same way that you partake of a delicious meal. (p.50-51)
Jesus in John 6:32-35
 Jesus then said to them, “Truly, truly, I say to you, it was not Moses who gave you the bread from heaven, but my Father gives you the true bread from heaven.  For the bread of God is he who comes down from heaven and gives life to the world.”  They said to him, “Sir, give us this bread always.”
 Jesus said to them, “I am the bread of life; whoever comes to me shall not hunger, and whoever believes in me shall never thirst.”