So a sin problem developed. God created man with the capacity to choose good or evil. Many choose evil as a pattern of life, and all of us often choose to do things contrary to God's will. The problem we face is that God is perfectly holy, he is perfectly righteous, and he is perfectly just, and on our own we have no way to get to him. There is nothing about us that would bring us to God on our own merit. The wages of sin is death.
So the problem is:
Before man was ever created, God the Father, Son, and Holy Spirit foresaw this problem, and decided that in the fullness of time that the Son, Jesus Christ, would give up the glory and majesty to which he was entitled as God, that he would be born as a human. He would live the perfect, sinless life, making him acceptable to God as the payment for sin. And since he is God, he is of infinite worth, therefore his death would pay for the sins of as many as choose to accept the wonderful gift of forgiveness.
His dad was a carpenter, and he learned that trade, but at the age of 30 he began his public ministry. Because his message of love and forgiveness was different from that of the religious establishment, a conflict arose between him and them, and after 3 years they conspired to put him to death, and did, by crucifixion. He was buried, and the third day he arose from the dead. In a few weeks he returned to heaven, and now sits on the right hand of God the Father. The penalty has been paid, and the procedure is simple:
Romans 10:9 For if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.
Philippians 2:12-13 So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence, work out your salvation with fear and trembling; for it is God who is at work in you, both to will and to work for His good pleasure.
Ephesians 2:8-10 For it is by grace you have been saved, through faith -- and this not from yourselves, it is the gift of God -- not by works, so that no one can boast. For we are God's workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do.