The first reading reaffirms that our faith and our choices in our faith are in fact choices.  We choose our religion and our actions.  In Joshua, the tribes of Israel have to make a choice -- do they worship the Lord, or do they worship the gods of their fathers or the gods of this new land.  Joshua says they can make their own choices, but that he chooses to worship the Lord.  They choose the Lord as well, knowing that if they revert to their old ways they may not get a second chance.  They realize that this choice is important and not a whim.  They choose the Lord, reiterate that decision, and pledge to it.  They acknowledge that the Lord has saved them and has seen them through hardships, and they will not forsake Him now that they are in relative safety.  But technically they could.  This is a choice and they have the free will to do that.  They choose the Lord and they choose this life.

The Psalm repeats this theme of choosing the Lord, blessing the Lord, praying to Him, and reaping His rewards, both here and forever.

The Gospel in a way deals with the idea of choices as well.  The children are brought to Jesus for his blessing, and the disciples try to send them away.  Jesus said, "Let the children come to me, and do not prevent them; for the Kingdom of heaven belongs to such as these."  Here he is reiterating what he said in the chapter before when the same disciples are arguing asking who is the greatest in the kingdom of heaven.  Jesus rebuked them then and held a child up and said "except you ... become as little children you shall not enter in to the kingdom of heaven."  He says whoever will humble himself as a little child will be the greatest in heaven and whoever would receive a child would the same receive Jesus.  Now here, just a short chapter later, the disciples are already forgetting what he said -- they are sending away the children.  And they are doing it for the same reason Jesus was using the children as examples.

The children hold no significance, no importance.  The adult men would be the significant ones and in the disciples' eyes those worthy of Jesus' attention.  But Jesus is blessing the children.  Jesus is not necessarily saying to be childish, or even childlike -- in innocence or ignorance.  Once a person is educated it's not really possible to go back.  Accepting faith with a childlike innocence is nice, choosing faith and all it entails from a position of knowledge is preferable.  Jesus knew his followers, like Joshua's, were making hard choices and choices that would hurt them in many ways -- in terms of status in the world.  Those who chose to follow Jesus would lose their worldly position -- would become as insignificant as children here in the world, but would have their reward as the greatest in heaven.