A Team Effort
Every thru hiker accomplishes their goal as a result of a team effort. Though the hiker expends the majority of the effort, no one makes it through without suppliers, hostels, trail maintenance crews and, hopefully, some Trail Angels along the way.
Each hiker succeeds, in part, because others contribute to their success.
Not so with God's plan of salvation. Christ alone accomplished everything necessary for sinners to be reconciled to God and know everlasting joy in Heaven. He is utterly unaided in any way by human effort.
To the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness - Romans 4:5.
For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast.
For all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus (Romans 3:23-24)
[Emphases mine].
Human effort does not contribute anything. On the cross, Christ paid the penalty in full and offers forgiveness as a gift!