There are not three separate gods but the three persons are somehow the one true God of the Bible. This relationship is called the Trinity. This is not easy to understand, yet it is taught in the Bible. The more we read in the Bible about who the Father, the Son and the Holy Ghost are, the more we come to know the real God of the Bible. Even though these three seem to be separate, they all claim to be the same God.
Trinity comes from tri-unity which means three in one.
The Triune God of the Bible separates true believers from false believers and non-Christians. For we are created in Christ Jesus to do good works which he has foreordained that we should walk in. God's salvation is free. There is no way anyone can earn or become worthy of it. God's true salvation separates the saved from the unsaved.