If there is fear of failure, it isn’t grace.  Grace doesn’t bring about fear, but relationship.  If your testimony with those who don’t believe in Jesus Christ doesn’t involve a reflection of liberty then you’re not showing them the glory of grace, but instead the legalism of what the flesh can do.  I won’t do various things if it will be a stumbling block for a brother, but I will walk in liberty otherwise.  I don’t fear failure, I embrace grace.