Friar's influence through marriage, these events would’ve been avoided, as the last thing Romeo and Juliet needed was more tension between each other. Another reason is that Romeo might have helped Mercutio fight Tybalt or not even started the fight if he didn't care to preserve himself above Mercutio so much, which he did only to indulge in Juliet's love in the future. If Friar did not marry them, Romeo would've cared more towards the argument with Tybalt, and the entire fight between the three might not have happened. As stated before the love they already had was amplified by Friar's actions, and considering how overemotional the two were before they were married, it did nothing to help the already chaotic situation. In Act IV, Scene I, Friar gives Juliet the sleeping potion/poison; however, this plan only caused more chaos. The reasoning behind the poison was to avoid the wedding of Juliet and Paris, and to fake the death of Juliet, all of which worked; however, when Romeo hears of the news of Juliet's supposed death, he rushes to where her body was kept, only to fight with Paris and lead the death of all three lovers. It created more chaos that could of been resolved if the potion didn't play a role, Friar insisting she fake her death did nothing to help the problem, and just served as a way to avoid the marriage, but not to solve the problem. Another example of the chaos that followed the potion is the letter that was supposed to be delivered to romeo by Friar John, but he was unable to, the letter contained info of Lawrence and Juliet's plan to fake her death. If Romeo received the message he would've known that Juliet wasn't really dead, and Romeo, Juliet, and Paris would still be alive. The chaos behind the potion wasn't justifiable, and for something that only ignored the problem it caused many more to follow with it, most of the blame goes towards the Friar for planning it out as he did. Some could think that it wasn't Lawrence's fault, and instead put the blame on Friar John for not being able to deliver the message; although, if Friar Lawrence told Romeo his plan to fake Juliet's death before, when it wasn't nearly impossible to get a hold of him, he wouldn't of needed to rely on Friar John and written paper.
The wedding between Paris and Juliet was known after the fight between Romeo and Tybalt, at this time Romeo was still in possible reach, and if Friar thought to pull something as complex as he did, he needed to inform Romeo with a small chance of failure. Friar Lawrence is to blame for expecting such a plan to work, and convincing Juliet he had it under control. Friar Lawrence knew the dangers of the misinformation that could be received on Romeo's end if the plan didn't work; based on his reaction to the failed delivery from Friar John, yet still he assured Juliet of his plan. Friar John was only an in between man, and his inability to deliver the letter should have been common sense, and Friar Lawrence shouldn't of risked so much to only ignore Juliet's arranged
marriage. In summary, Friar Lawrence is to blame because he created more tension of love between the two by marrying them, which lead to Tybalt's death, and the death of all three lovers by his makeshift plan of faking Juliet's death with a sleeping potion. Friar Lawrence's advice and plans, though respectable, created much of the chaos throughout the play, and weren't worthy enough to ensure the couples relationship. Though many made mistakes throughout the story of Romeo and Juliet, Friar was most responsible for adding more to the already large fire, and killing the three lovers.