The 18th verse is applied to the church and no individual. To bind in this particular case is the judgement of the church guided by God's wisdom. To loose means to, as Drich said, is to forgive through God's wisdom. God would trust no one to decide what will happen to people or forgiveness of people without it being taught by Him, this is why we have the Bible and prayer, to know what God desires us to do in judgement. God would never allow bad decisions made on earth to be a part of His perfect eternal kingdom. Being able to have the personal relationship with God means God can work through many individuals (the Church) to teach us to honestly judge other Christians through His taught wisdom. God's teachings are so to speak black and white, so anyone delving into the gray may be wrong, that's why God uses the majority in the church to decide, it will eliminate those delving into the gray areas and hopefully they will learn from the experience.
I guess this is more than you wanted, but you asked a question that actually takes more than one verse to explain. There's much more to it than anyone has explained, we were trying to give you something less complicated.
GC
I guess this is more than you wanted, but you asked a question that actually takes more than one verse to explain. There's much more to it than anyone has explained, we were trying to give you something less complicated.
GC
God loves those who believe and those who do not and the same goes for me, you have no choice in this matter. That puts the matter of total free will to rest.