The faith that you have, keep between yourself and God. Blessed is the one who has no reason to pass judgment on himself for what he approves. (ESV)
Paul is not talking in this verse about saving faith, the faith that is required to receive our salvation in Christ. We know that every step of our life after we receive the forgiveness of Jesus Christ is a step of faith. He leads. We follow. We have faith in his direction in our lives. The more that we walk in that faith the more we grow mature.
Paul is telling us that our faith in God is a personal faith. If we have grown in our mature walk with Christ and we know that we have freedom in that faith, then we will use that freedom in a way that respects others. If there are certain things that we are free to do in Christ that would make another brother stumble we keep the expression of that freedom between ourselves and God.
Blessed is the one who has no reason to pass judgment on himself. In other words, the mature believer has a finely tuned conscience. The mature believer has grown so in love with Jesus Christ that he would not want to do anything that would offend the Savior. The mature believer is one who spends time in the Word of God so that his actions are directed by the Scripture.
We are to work on our faith in Christ. We placed our faith in him at salvation, but our faith is also a daily walk. It is inexcusable for us to be immature in our faith if we have walked with him for a long time. We need to draw so close to him that he directs every aspect of our lives. What will be the result? Blessing.
How is your faith? Your daily faith? Are you drawing closer to Christ? Fine tuning your conscience? Reading God's Word? Allowing Scripture to direct you decisions? You can expect blessing!