John 20:30 Now Jesus did many other signs in the presence of the disciples, which are not written in this book; but these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name.
Luke 1:3-4 it seemed good to me also, having followed all things closely for some time past, to write an orderly account for you, most excellent Theophilus, that you may have certainty concerning the things you have been taught.
Romans 15:4 For whatever was written in former days was written for our instruction, that through endurance and through the encouragement of the Scriptures we might have hope.
1 Corinthians 10:11 Now these things happened to them as an example, but they were written down for our instruction, on whom the end of the ages has come.
2 Timothy 3:15-17 and how from childhood you have been acquainted with the sacred writings, which are able to make you wise for salvation through faith in Christ Jesus. All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work.
The Gospel – and all of the Bible – was written so that we may believe, not that we might doubt. “There is no text in the whole Book which was intended to create doubt. Doubt is a seed self-sown, or sown by the devil, and it usually springs up with more than sufficient abundance without our care.” (Spurgeon)
John understood that faith in Jesus as Messiah and God had value beyond the honorable recognition of truth. It also carried the promise of life in His name. This was the life that transformed John himself, and he wanted that same life and transformation for all through his Gospel account. This belief isn’t complicated. Our response is as simple as ABC: Accept, Believe, and Commit. It isn’t always easy, but it isn’t complicated.
We do try to complicate the gospel. We try to understand it with human understanding and human wisdom. The human side of understanding will try to make sense of Jesus Christ, redemption, forgiveness, and salvation by means of doing more good things than bad and thereby being good enough to deserve redemption and forgiveness. Scripture does not say “To whom so ever is good enough, God sent His one and only Son”. It does say that “God so loved the world, that He sent His one and only Son.” It is by grace, mercy, and love we have access to redemption, salvation, and forgiveness through Jesus Christ. The point being, you will never be good enough or do enough good to warrant eternal life through Jesus Christ. When the human mind is able to cast these thoughts aside, faith is born and godly wisdom and understanding take root. It is only then that we can begin to faintly grasp a sliver of the magnitude of God’s grace, mercy, and love.