Jn 17:3 Now this is eternal life; that they may know you, the only true God, and Jesus Christ, whom you have sent

Some people say that we don't need to keep Passover because the Bible says that knowing God is eternal life.

Above verse is teaching of Jesus. Jesus who taught us that knowing God is eternal life also taught us that we can have eternal life through Passover.

Jn 6:53~54 Jesus said to them, "I tell you the truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day."

This teaching means that we should eat the flesh of Jesus and drink the blood of Jesus to receive eternal life. Despite of the teaching, can we insist that we don't need to eat and drink his flesh and blood? Those who truly believe in Jesus can't.

These two teachings, knowing God is eternal life and the one who eats Jesus' flesh and drink his blood has eternal life, actually have same meanings. Because, to know God, we must keep the new covenant.

Jer 31:31 "The time is coming," declares the LORD "when I will make a new covenant with the house of Israel and with the house of Judah. ... This is the covenant I will make with the house of Israel after that time," declares the LORD. "I will put my law in their minds and write it on their hearts. I will be their God, and they will be my people. No longer will a man teach his neighbor, or a man his brother, saying 'Know the LORD.' because they know me, from the least of them to the greatest," ...

Those who have the new covenant which God promise to establish in the new testament will know God enough not to say 'Know God'. This means that we should keep the new covenant and put it our minds so that we can receive eternal life.
And the core of the new covenant is Passover as Jesus established the new covenant with the wine of Passover.(Lk 22:15) . Therefore by keeping Passover we can know God. That's why Jesus taught above two teachings as these are same meanings.

Therefore the insistence that we don't have to keep Passover is false insistence which comes from ignorance that doesn't understand the will of Jesus.