If it were simple, no Bible study would be required.
John 3:16 is enough of a door to salvation for a whole lot of people. The rest (as a Jewish sage once put it) is commentary....
Receiving salvation is not, as the Bible makes clear, in distinction to living out that faith, and studying the Bible we see how simple it is for a soul to pass from death to life.
The penitent publican who "would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner" simply cast Himself upon the mercy of the God of the Bible (who provides atonement for sin) in the light of his damnable destitute condition, (L13,14) and the "good thief" (a unspecified criminal actually) did likewise, reproving his scornful counterpart, "for we receive the due reward of our deeds: but this man hath done nothing amiss," and asking the Lord for mercy, "Jesus, Lord, remember me when thou comest into thy kingdom." (Luke 23:41,42)
Similarly, the 3k saved at Pentecost, after about a 7 minute message on the Scriptural fulfillment the miracle they were witnessing, and of Christ as the Messiah, and being convicted of their sins and the judgment they were worthy of (the major work), "were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do? Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. " (Acts 2:37-38)
And the next recorded major address was even shorter (209 words), culminating with the invitation, "To him give all the prophets witness, that through his name whosoever believeth in him shall receive remission of sins." (Acts 10:43) And which they promptly believed and received.
Thus becoming a born again a child of God does not take any real study, but a humble contrite heart that sees its need for salvation, and hears about Christ and what He basically did, and wants a new life with Christ, and thus trusts in the Son sent by the Father to be the Savior of the world. Thanks be to God.