The evidence that you have been forgiven by God is that you are forgiving to others.
The evidence that you are forgiving to others is in your freedom from all bitterness, anger, or ill-will towards anyone.
The evidence that you are free from all bitterness, anger, or ill-will towards anyone, is the compassion, kindness, and gentleness you show towards all people.
The evidence that you have compassion, kindness, and gentleness with all people is seen in how you handle those who "don't deserve it".
Forgiveness is not necessarily trust. You can forgive someone that you will not trust; you just have to have the genuine wish that you could. Forgiveness is not necessarily rescuing someone from consequences. You can forgive someone who is suffering consequences; you just can't have any secret enjoyment about it. Forgiveness is not necessarily "becoming their best friend"; but it is an authentic capacity to do so freely.
But forgiveness IS forgiveness. And if you don't give it freely, from way down deep, wholly and completely, from the heart, you may need to question if you yourself have yet experienced the full, life-transforming touch of the forgiveness of God.
There is no excuse to be unclear about when and where forgiveness is to be applied by the disciple. Jesus says, "forgive everyone" (Lk 11:4) and Paul adds, "whatever the grievance" ( Col 3:13).
In Luke 6:37 Jesus says, "Do not judge, and you will not be judged. Do not condemn, and you will not be condemned. Forgive, and you will be forgiven." And then in Matthew 18:35 He adds, "This is how my heavenly Father will treat each of you unless you forgive your brother from your heart."