The mantra of many a congregation is that everyone is welcome to attend their church 'just as they are.' This usually -- and rightfully -- means that those outside the church should feel comfortable to attend without changing themselves to look like those inside. (One would hope that no one means, by 'come as you are', that they arrive in the same condition as when they had just gotten out of the shower.)
We also say that God welcomes sinners 'just as they are.' When this means that one need not become holy before coming to God, it is an accurate representation of biblical teaching, for no one can be holy without God, and everyone comes to God with only his sinful condition in hand. It is after one has come to God that God makes those changes, where necessary.
Frequently, however, what we truly mean when we recite these phrases, and what we are teaching those we attempt to invite by uttering them, is 'Come as you are, and leave as you came.' But the Bible tells us that if a man has actually come to God, he will leave a different man. Not necessarily different in his outward, physical appearance, but different either in that his standing has shown confirmed in his rejection or acceptance of God, or different in the attitudes of his heart having met the living God.
Sure, 'Come as you are,' but leave as God wills.