In the garden of Eden, there were two trees, The “Tree of Life” and the “Tree of Knowledge” The fruit of the tree of life gives eternal life, in John 17:3 Jesus says “Now this is eternal life: that they may know you, the only true God, and Jesus Christ, whom you have sent.” So eternal life is knowing God, or a life that depends solely on God. The fruit of the tree of knowledge gives us the ability to decide what is good and bad for us, that’s a life independent of God. So it was a choice for mankind whether be depend on God or to be independent of him. And man choose to be independent of God
When man sinned, his spirit died and with that the man lost contact with God. But God didn’t want to lose man, so he send his only begotten son Jesus to save the mankind.
Jesus said, to be in the Kingdom of God, man needs to be born again, it means the spirit of the man that died due to sins need to live again… true life need to come back into man, only then the gap between man and God can be bridged. Jesus said “I am the way the truth and the life”. He came to give life and life in abundance. He who know no sin became sin and died for us, He redeemed us from the wages of sin, once and for all.
So by accepting Jesus as our Lord and Saviour and believing in him we get saved, we will become a new creation, in other words our dead spirit will be born again. Once we are born again, our spirit comes back to life and we will be able to know God.
Going to a church or following some doctrines or doing good deeds to compensate our sins will never save you. To be saved you need a saviour and that’s Jesus Christ. Romans 10:9 That if you confess with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved. Ephesians 2:8 For it is by grace you have been saved, through faith—and this not from yourselves, it is the gift of God
Christian life is a life lived by faith, fully dependent on God. He knows everything and always does what is good for us, so its better to be dependent on Him rather than doing anything on our own.