Contradiction with John 14:6
Jesus claims to be the only way to the Father, implying exclusivity in access, contrasting the open access suggested in Psalms 118:20.
John 14:6: Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
Contradiction with Acts 4:12
States salvation is found in no one else, implying exclusivity, in contrast to the open gate in Psalms 118:20.
Acts 4:12: Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved.
Contradiction with Matthew 7:14
Describes the gate as narrow and difficult, contradicting the righteousness and ease implied in Psalms 118:20.
Matthew 7:14: Because strait [is] the gate, and narrow [is] the way, which leadeth unto life, and few there be that find it. [Because: or, How]