Read Mark 9:38-50
38 John said to him, “Teacher, we saw a man who was driving out demons in your name, and we told him to stop, because he doesn’t belong to our group.”
39 “Do not try to stop him,” Jesus told them, “because no one who performs a miracle in my name will be able soon afterwards to say evil things about me. 40For whoever is not against us is for us. 41I assure you that anyone who gives you a drink of water because you belong to me will certainly receive his reward.
42 “If anyone should cause one of these little ones to lose his faith in me, it would be better for that person to have a large millstone tied round his neck and be thrown into the sea. 43So if your hand makes you lose your faith, cut it off! It is better for you to enter life without a hand than to keep both hands and go off to hell, to the fire that never goes out.o 45And if your foot makes you lose your faith, cut it off! It is better for you to enter life without a foot than to keep both feet and be thrown into hell.p 47And if your eye makes you lose your faith, take it out! It is better for you to enter the Kingdom of God with only one eye than to keep both eyes and be thrown into hell. 48There ‘the worms that eat them never die, and the fire that burns them is never put out.’
49 “Everyone will be purified by fire as a sacrifice is purified by salt.
50 “Salt is good; but if it loses its saltiness, how can you make it salty again?
“Have the salt of friendship among yourselves, and live in peace with one another.”
Already in the time of Jesus there seem to have been some 'denominational' differences - people were casting out demons; but they weren't part of the group of disciples. Jesus' accepts the work they are doing and encourages the disciples to appreciate all work done for the sake of the Kingdom.
In verse 50 Jesus reminds his disciples: "Have salt in yourselves, and be at peace with one another."
Lord, salt cleanses wounds and cleans things. May your salt cleanse my wounds and heal my heart so that I may go out and heal others in your name.