John was a believer in Jesus Christ and a believer in the Bible. He encouraged his kids to memorize scripture, and they did! Therefore, as part of honoring him and God -in whom he believed- I will take a few moments to define his faith.
One of his favorite passages of scripture was from the Old Testament book of Proverbs, chapter 3, verses 5 and 6 which read,
"Trust in the Lord with all your heart and do not lean on your own understanding. In all your ways acknowledge Him, and He will make your paths straight."
It says, "Trust in the Lord." Well, who is the Lord? In the Hebrew language, the name behind the word 'Lord' here is 'Jehovah.' The basic meaning is 'to exist,' but the critical part of the meaning is 'to self-exist.' This means that God Himself has no creator: no one created God. As such, He is eternal. He has no beginning, no end, and He is not subject to entropy, aging, decay, or the wear and tear of time. He is not subject to death, which John was, and we all are. He is God as defined in the Bible, both Old and New Testaments. He is the uncreated Creator. He created all physical reality, the heavens and the earth, including humans, us.
The verse says, "Trust in the Lord," and the question can be asked, "How can I trust in God unless I have information about Him that I can rely on?" The Bible is this information. The Bible is His word to us. Not just information about Himself, but revelation from Him to us about everything pertaining to existence and humanity. And so, as it says, "Trust in the Lord," it means to trust in all that He has revealed about Himself to us. In the scriptures, the word 'trust' is a life impacting word. It means to attach oneself with the result of being safe, confident, secure, without care. It means 'to rely on.' The idea is associated with firmness and solidity. It expresses that sense of rest and well-being in knowing that the rug won't be pulled out from under you. It is a confident expectation as opposed to a constant anxiety. The beginning of trust, then, is to attach oneself (attach oneself to God). But how is this done? How do we find God in order to attach ourselves to Him?
The ancient pagan world was haunted by the unknowability -or obscurity- of God. Plato wrote, "It is hard to investigate and to find the framer and the father of the universe. And, if one did find him, it would be impossible to express him in terms which all could understand." So, if God seems obscure, hard to find and know, how is this remedied? The remedy is Jesus Christ.
In the Gospel of John, chapter 14, verse 8, one of the followers of Jesus, Philip, asked Him, "Lord, show us the Father." As Philip used the term Father, he was referring to the same self-existent one as Pr. 3:5 refers to as it says, "Trust in the Lord." Lord and Father are one and the same. So, Philip said to Jesus, "Show us the Father/Lord/Self-Existent One." The response of Jesus was, "He who has seen Me has seen the Father." Or, as Heb. 1:3 says,
"[Jesus] is the radiance of [the Father's] glory and the exact representation of His nature."
But How can Jesus be the radiance and the exact representation of the fulness of God? This is because of the nature of God. God is Triune, 3 Persons in One: God the Father, God the Son, God the Holy Spirit, all co-equal, so Jesus can express the Father in fulness which Plato could not.
And so, now the question, why is God hard to find and why is Jesus the answer? God is hard to find because people are sinners and God is not, and the distinction between the sinfulness of people and the holiness of God is beyond human comprehension. God did not create humans as sinners, but He did create us moral beings. Adam and Eve were created pure, but they fell into sin and their nature was corrupted (fallen). They passed on their fallen nature to all the future human race, including us, and as such, we fall short and sin. As Rom. 3:23 says,
"For all have sinned and fall short of the glory of God."
The fullness of who He is, the fullness of His life, what a human should be.
I think the evidence that humans are sinners is much. It is this sinfulness that separates us from God and makes Him unknowable. Part of the condition of this fallen nature is the inability to fix itself. Humans cannot fix their sinfulness, and all sins will be judged by God and the person condemned. This is where Jesus is the remedy. Jesus existed as God before the creation of the earth. Then He lowered Himself to become human through a physical birth. But, the seed of His birth was God the Father, through the Holy Spirit, but was of a virgin. Thus, He was Holy at birth, untainted by human sin and human fallenness. He grew up and died on the cross as a sacrifice for our sins. The punishment of God against us because of our sin was poured out upon Jesus Christ. As 1 Pet. 3:18 says,
"For Christ also died for sins once for all, the just for the unjust, so that He might bring us to God."
If we recognize our sinfulness and acknowledge it, and ask Jesus to forgive us of our sins, believe in and receive Him, our sins are then forgiven, and we escape the future judgement. But we also, when we receive Jesus, experience a new spiritual birth and enter into eternal life through it. Our separation from God is healed. We come into union with Him. Or, as part of the definition of trust in Pr. 3:5, we attach ourselves to Him and we can then trust Him in such a way as to find rest and solidity in this world with the assurance of heaven and eternal life beyond it.