A great example is in 2 Chronicles 30. Hezekiah has instigated something of a spiritual homecoming for the wider populace, and is marking it with a passover celebration (the first in many years apparently). The passover came with regulations, conditions, rules about 'how it should be done'. In the gathering momentum of so many turning up to take part, there are a good number who don't meet the requirements but join in anyway. Hezekiah's prayer is instructive:
May the Lord, who is good, pardon everyone who sets their heart on seeking God ... even if they are not clean according to the rules.
See verses 18 to 20: The Lord heard this prayer! Grace over-rides law.
Interestingly we are told that the Lord 'healed' the people - as if they had an ailment or condition. But just as God can heal our medical issues, He can resolve our spiritual-uncleanness issues as well (cross reference Jesus and the man lowered through the roof, e.g. Matthew 9:1-8).
When our understanding of the Christian faith somehow slips back to rules and requirements for newcomers (or even home-comers!), let us remember and use Hezekiah's short prayer, and the grace-trumps-law principle it embodies.