Maintain Humility

Romans 11:17 But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree, 18 do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you. 19 Then you will say, “Branches were broken off so that I might be grafted in.” 20 That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear. 21 For if God did not spare the natural branches, neither will he spare you. 22 Note then the kindness and the severity of God: severity toward those who have fallen, but God's kindness to you, provided you continue in his kindness. Otherwise you too will be cut off. 

It is very possible to become a spiritual snob.  That was a problem in Jesus' day and in Saul's.  The scribes and Pharisees (for the most part) were too proud to give up trusting in themselves and trust in Christ, thus also influencing many Jews to not trust in Him either.  But Paul refused to give up on his people, and he challenges us not to give up on them either; in fact, he warns us against spiritual self-righteousness against any person or group as being beyond the saving power of Christ.  If we are spiritually proud, we are not trusting in Him, and that's the last place we want to be.