All people are fantastic at understanding the Purpose of Christ, but few recognize the Effectual Work of Christ. The Core of the Gospel, which I have never heard one person preach thereof, is Colossians 2:9-15.
Let me make this 100% perfectly clear - In order to receive Eternal Life, a person MUST have their Heart Circumcised by Christ. Why do people not adhere to these Seven Perfect Verses? Because if they did, they'd realize that their out-of-control sin will prove that they are not saved. Anyone with a Circumcised Heart will be exactly as Abraham . . . to walk blamelessly before the Lord.
The Bible is clear: We MUST possess the Faith of Abraham, and that Faith comes by way of a Circumcised Heart, which is the simple lifting of the Curse that was instituted from the Garden of Eden.
To understand the Gospel, we must know both the Purpose of Christ and the Work of Christ, which is the only Work that saves souls.
Colossians 2:9-15 KJV - "For in him dwelleth all the fulness of the Godhead bodily. 10 And ye are complete in him, which is the head of all principality and power: 11 In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ: 12 Buried with him in baptism, wherein also ye are risen with [him] through the faith of the operation of God, who hath raised him from the dead. 13 And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, having forgiven you all trespasses; 14 Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross; 15 [And] having spoiled principalities and powers, he made a shew of them openly, triumphing over them in it."