I am praying not only for these disciples but also for all who will ever believe in me through their message. I pray that they will all be one, just as you and I are one — as you are in me, Father, and I am in you. And may they be in us so that the world will believe you sent me. (John 17.20-21 NLT)

Unity is difficult to achieve. Self always gets in the way.

And in this specific prayer, Jesus prayed that there be unity amongst us and unity with him and the Father "so that the world will believe".

Miraculous healings are amazing and glorifying God, but Jesus did not pray for that to be given to us: "all who will ever believe in me". In his private prayer alone with God, Jesus prayed for "all who will ever believe in me" to be in unity.

Let us strive for unity amongst believers.

Don’t be selfish; don’t try to impress others. Be humble, thinking of others as better than yourselves. Don’t look out only for your own interests, but take an interest in others, too. You must have the same attitude that Christ Jesus had. Though he was God, he did not think of equality with God as something to cling to. (Philippians 2.3-6 NLT)