Basically, it all depends on your current Level of Consciousness (LOC). Naturally, you need to act according to the spiritual principles of forgiveness, compassion, mercy and love.
But, how you apply them in practice, depends on your perception and degree of your spiritual maturity.
At the same time, we need to be aware that Earthly life affords maximum karmic opportunities to acquire good karma, and undo negative karma. As Buddha said, to be born human is a great gift, for it affords us maximum potential for spiritual growth.

Talking about karma, it is commonly believed that Christianity doesn’t teach karma; that’s not exactly true.
Although it doesn’t use the specific term, Christianity teaches that sin and virtue have very different consequences for the soul, after death.
Karmic alternatives: heaven, purgatory and hell are the destiny of Christians as the consequence of their lives.

Followers of Buddhism will enter the Lotus Land, an equivalent of heaven, where an aspect of Buddha speaks as their advocate.
Krishna said that those who worship and love God by whatever name, are “Mine and dear to Me.”
It is important that we perceive our human existence as the primary spiritual gift, and an opportunity for our free will to choose or reject Divinity by whatever name God is known.

Affairs of the World are interpreted in accordance with one’s Level of Consciousness. Thus for some, the world may appear sad, tragic or miserable. For others, it will seem challenging, exciting or tempting. Human life presents for consciousness a great spiritual gift to evolve, and even reach Enlightenment; thus realize the Self.
Although worldly life is brief and transitory, its consequences are profound indeed and long term. It is wise to value the opportunity and treat spiritual endeavor as an expression of appreciation for the gift of life.