I remember vividly the first time I read through the passage in Exodus 12 describing God’s instructions to the Israelites for the initial Passover.
The Lord impressed on my spirit that while the blood was necessary (sacrifice had to be made) it was obedience of each person to place themselves under that blood that saved them from the death angel.
They were spared because they believed and acted according to that belief, trusting God to do what He said He would do.
It’s the same with the blood of Christ-He is the sufficient Sacrifice and the full payment for sin.
Read the rest here: Lenten Reflections: Fasting “Adding” To The Sufficiency of Christ’s Sacrifice