Everybody has a belief about God. It can get pretty confusing trying to sort out what to believe about God. With all the different religions, with different branches of Christianity, thousands of denominations, millions of churches...
But there are some core beliefs that Christians have about God, and one of them comes from our Jewish roots is central to our understanding of God. It comes from a famous prayer, called the Shema: Hear O Israel: the LORD our God, the LORD is one. Love the LORD your God with all your heart and with all your soul and with all your strength.
According to some Jewish theologians, there are three traditional points drawn out of this prayer: God is NOT none, God is NOT two, God is NOT many. In believing that God is one, we believe that God does exist, that he has integrity - thus is not a god of good and a god of evil, and that God is not polytheistic - there is only one of him and he has all the power often attributed/distributed to thousands of other little gods.
What we believe about God shapes our life. Often times our actions reveal what we actually believe about God. Saying we believe something about God is not quite the same as living out a belief about God. Which is why it is important to take moments to reflect on what you really do believe about God. If you want your life to be different, you may need to absorb some different beliefs about God - or fully absorb the right ones you have in your head, and get them into your heart and hands.
It's in this direction that Paul is going when he writes to the Christians in Ephesus, trying to help them make a connection between their belief in the One God and their actions towards God and neighbor.
As a prisoner for the Lord, then, I urge you to live a life worthy of the calling you have received.Our belief in the One God ought to bring about an integrity in our own lives and a unity with the lives of others. Just as we have to work at understanding our belief in One God and Father of All, so we have to work at integrity and unity. When we pour little effort into our integrity, when we dismiss the value of unity - we reveal what we believe about God.
Be completely humble and gentle; be patient, bearing with one another in love.
Make every effort to keep the unity of the Spirit through the bond of peace.
There is one body and one Spirit,
just as you were called to one hope
when you were called;
one Lord, one faith, one baptism;
one God and Father of all,
who is over all and through all and in all.
Ephesians 4v1-6 [TNIV]
Integrity isn't about convincing people that you have it all together, and unity isn't about pretending that everything is fine with you and someone else. Integrity is being honest with yourself and God and others about who your really are - and about your work to become one person with yourself, God, and others. Unity is the social side of integrity - connecting to others as they really are - working in a spirit of justice and mercy.
Paul goes on to say that we are to "walk in the way of love." If we're going to believe that God is One, then integrity and unity are going to be central to our life, to our way of doing life, to our walk of love. If you are convicted over your lack of integrity, over your lack of unity, then confess it, repent, and seek out help to strengthen your belief in the One God, the One Lord, the One Spirit.