here is another fantastic “gospel definition”.so beautifully worded, biblically faithful, and gloriously true. if you  don’t know much about j.i. packer, read “knowing god” as soon as you can.

To the question; what must I do to be saved? the old gospel replies; believe on the Lord Jesus Christ. To the further question; what does it mean to believe on the Lord Jesus Christ?; its reply is; it means knowing oneself to be a sinner, and Christ to have died for sinners; abandoning all self-righteousness and self-confidence, and casting oneself wholly upon Him for pardon and peace; and exchanging one’s natural enmity and rebellion against God for a spirit of grateful submission to the will of Christ through the renewing of one’s heart by the Holy Ghost.

-j.i. packer