To "obey the Gospel" is to BELIEVE IT. = That is how you obey it as.. "ALL that believe in Jesus shall be saved"..
"All who call on the name of Jesus shall be saved"
Understand... that to "receive Christ as your Savior" is to have BELIEVED ""the Gospel of the Grace of God"
Once you do that, you are born again by the Holy Spirit, and have entered through "the Narrow Gate" = who is Jesus, Himself.
"I am the ONLY WAY... (narrow way) to the FATHER.."""
This is the : CROSS of CHRIST
There is your "Narrow Way".....and all other "ways" are the "broad WAY .. that leads to destruction"... =(Hell) .
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King James Bible
But as many as received (Jesus), to them gave he power to become the sons of God, even to them that believe on his name:
New King James Version
But as many as received Him, to them He gave the right to become children of God, to those who believe in His name:
American Standard Version
But as many as received him, to them gave he the right to become children of God, even to them that believe on his name:
Berean Study Bible
But to all who did receive Him, to those who believed in His name, He gave the right to become children of God—
Douay-Rheims Bible
But as many as received (Jesus), he gave them power to be made the sons of God, to them that believe in his name.
English Revised Version
But as many as received him, to them gave he the right to become children of God, even to them that believe on his name:
World English Bible
But as many as received him, to them he gave the right to become God's children, to those who believe in his name:
Young's Literal Translation
but as many as did receive him to them he gave authority to become sons of God -- to those believing in his name,