Ephes. 4:1-7 (ESV)
I therefore, a prisoner for the Lord, urge you to walk in a manner worthy of the calling to which you have been called,  with all humility and gentleness, with patience, bearing with one another in love,  eager to maintain the unity of the Spirit in the bond of peace.  There is one body and one Spirit—just as you were called to the one hope that belongs to your call—  one Lord, one faith, one baptism,  one God and Father of all, who is over all and through all and in all.  But grace was given to each one of us according to the measure of Christ's gift.
Paul here begins to get down to the dynamics of congregational life, how we should respond to each other, bearing with one another in love. Sometimes we forget to forgive those in the church. Outside the church perhaps we find it easier to forgive, we think they don’t know any better. But those in the church we think they ought to know better, so we are less apt to forgive. But sinners are sinners no matter where they are found, and whether or not they know better is beside the point. Sinners sin against God and each other, and need to be forgiven. That is what we live by. Forgiveness. So having been forgiven by the grace of God, given to each of us according to the measure of Christ’s gift, we forgive each other, and in this way bear with one another, and so maintain the unity of the Spirit in the bond of peace.
Paul goes on to explain this unity. We are one, because there is only one body, and one Spirit, one hope, the gospel by which you were called. There is only one gospel, the forgiveness of sins won by Christ on the Cross with his death and resurrection. No other. There is not one gospel for you and one for me. Not one gospel for our church and another for a different church. There is not one gospel for gentiles and another for Jews. There is one gospel for all and it unites all. Just as there is only one Lord, one Faith and ONE BAPTISM, one God and Father of all.
I emphasize this one baptism. Today the church at large is all over the map on this. Some churches believe that there is actually two baptisms, one of water and the other of the Holy Spirit. Others feel free to baptize people over and over and over, but refuse to baptize an infant. It is confusion. There is one baptism for the Christian, Baptism of the water and the word through which we are sanctified by the work of the Spirit. We all share this one baptism and by it become members of the one body of Christ. If the spirit has given you other gifts great, but that was not a baptism. You are no more sanctified than the little child baptized last week with the water and the word. And as for rebaptizing yourself, don’t. God makes a promise to you in baptism. That promise is good for life. He forgives your sins. It doesn’t matter that you sinned last week, you don’t have to be baptized every time you repent. Stop pledging yourself for God, you only heap on the guilt. You are not going to do a better job keeping your promise to God than you did last week. So let your yes be yes and your no be no. But stop making empty vows to God. He has pledged himself to you in baptism. If you also pledged yourself to God and broke that pledge, it does not mean God has broken his. He still forgives. Your baptism took, now live in it. Don’t make God out to be a liar, and a promise breaker by rebaptizing yourself.