In plain words
The poet, of the Lord's grace: Now I know it: except for those who go by the unfailing path of my father at beautiful Araṅgam [taking him alone as the means], all who try by themselves to cut their way out of the thicket-like hell of worldly bondage, which cannot be broken, will find the door at the gate of the immortals' well-guarded city [Paramapadam] shut before they can get there.