unto whom all hearts be open,
all desires known,
and from whom no secrets are hid;
Cleanse the thoughts of our hearts by the inspiration of thy Holy Spirit,
that we may perfectly love thee,
and worthily magnify thy holy Name;
through Christ our Lord. Amen.
This is another beautiful collect taken from the Anglican Book of Common Prayer. It is used during service of Holy Communion. It is generally known as the 'Collect for Purity'. For any Christian believer, it is a prayer that might be used at other times.