Titus 3:5 not by works of righteousness which we have done, but according to His mercy He saved us, through the washing of regeneration and renewing of the Holy Spirit,
Christ has demonstrated the ultimate instance of kindness and love that anyone could think of in giving us Salvation through His actions.
It is not because of the thing that He has done but the mercy He has shown us that we know this to be true.
Martyrs have come and gone, but it is the love and demonstration of that love which stands out for me.
It is the Holy Spirit who can open up our hearts to what Christ has done when we start to listen with our hearts.