This is how Jesus illustrates the life of vibrant, fruit-bearing faith in John 15. "Abide in Me, and I in you. As the branch cannot bear fruit of itself unless it abides in the vine, so neither can you unless you abide in Me." (John 15:4) What is fruit? "The fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control." (Galations 5:22) Those qualities don't come to us because we try really hard to produce them; they grow into our character when we abide in Christ.
This is a very simple principle that none of us need a doctor of divinity to understand: Just as the life of the vine flows through to the branches, so the abundant life of Christ flows through to us when we abide in him. This is the apex, the simple Truth that silences bickering theologians, the wisdom that God has hidden from the wise and intelligent and revealed to infants.
What does it look like to abide in Christ? If you read no other Christian book this year (or this decade for that matter), I would recommend The Practice of the Presence of God, by Brother Lawrence, an uneducated French lay brother who lived in the 1600s. The book, quite simply, demonstrates what it means to walk with God in faith and obedience. Brother Lawrence tried always to abide in God's presence like a branch on the vine.
My version is sixty-two pages with a lot of white space, and in that small volume Brother Lawrence demonstrates true repentance and spiritual rebirth, the relationship between faith and works, justification and sanctification by faith, and eternal security based on faith, not presumption. But he is no theologian, and he doesn't use any of those words. His words are simple and direct, and he allows us a clear view into his soul, including his struggles.
Brother Lawrence never actually sat down and wrote the book. It is a compilation of letters written by him and notes taken by someone else during conversations with him. Important people came from everywhere to meet this humble, uniquely Spirit-filled monk and learn his secret. Over the years, he has been loved by Protestants and Catholics, Arminians and Calvinists alike, because he focused on the Treasure itself, not just words describing it. He dispensed with form and sought the substance. In short, he lived a true John 15 life of faith.
Why did Jesus come? In his own words: "I came that they may have life, and have it abundantly." (John 10:10) John 15 demonstrates how we may receive it.