The Prophet (sal Allahu alaihi wa sallam) said: “The key to Paradise is prayer (salat), and the key to prayer is ritual purity (tuhur).” [Ahmed]
Paradise has eight doors. If you have the key to a door, you can turn the key in the lock and the door easily opens for you. If, on the other hand, you don’t have the keys, you could keep trying other keys that don't fit, or attempt to break the door down. When the keys are easily available though, only a foolhardy person would insist on trying wrong keys, or try to get in by breaking the door down. The keys to Jannah have been given to you. Don't waste your time with trying wrong ones. The keys to Jannah are the obligatory five daily prayers. And purification of the body, through wudhu and ghusl, are the keys to the prayer.