In response to a question about Federal Vision, I wrote the following.
Federal Vision (FV) is defined by its advocates here. I'd advise a close reading of this before reading what other people write about FV. Or if that's too late, letting this source document drive your determination of FV's soundness, instead of other people's hyperventilations.
My own summary: FV emphasizes and calls us to operate on the covenant God has given us to see and deal with (Word, sacraments, visible church), more than the secret decrees of God (election, perseverance, etc.). FV does not deny the latter, but sees pitfalls in trying to read the secret decrees in people sitting in the pew. God's covenant with us is objective (sacraments and actions) and subjective (inner heart of faith). FV again emphasizes the former without denying the importance of the latter. (This leads to the practice of children taking communion: they are objectively baptized, and their subjective experience of faith will be shaped/fed by the objective practice.) These objective/subjective pairs need not be pitted against each other.
FV also teaches that Adam before the fall could not strictly merit God's favor, because the covenant He set up already graciously gave him life. Obedience would have come from faith in God, just as it does for us.
Other issues like post-millennialism and higher liturgy in worship also play a part in defining FV folks.
I consider myself a mild advocate of the above view. This means I agree with it, but don't think the world will end without my emphasizing FV distinctives in my local church and getting everybody on board.
The CREC does not have an official position on faith alone, other than to affirm it in the presbyterian confessions it endorses. We have this, from the FV advocates themselves in the statement linked above: "we are all agreed that no one is justified at any time because they personally have earned or merited anything."
Several presbyterian denominations have condemned FV, assuming or afraid that it denies or leads to denying justification by faith alone. This is not true. I appreciate their zeal for orthodoxy, but not their lack of charity in condemning people for holding positions they do not hold.
Sacraments are not required in addition to faith for salvation. But we do expect sacraments to make a real, faith-building difference in the life of believers. Part of the FV emphasis is on the earthly things God has given us impacting our spiritual lives, rather than shutting out the world so as to better focus on the spiritual realm. We are trying to recover from a bad spiritual/earthly dualism.
Hope this helps.