In john 14:6, Jesus said, “I am the way, the truth, and the life. No one comes through to the father except through me. Coming through Jesus is what gives us the power, the capacity to access God.
The door is always open, but to enter that door we must acknowledge that we need this provision by God and that through and by Jesus, we will be saved. The door is open to all, no matter where we are at in our own life, there is provision for just for us to come to God through Jesus.
The gate is narrow in the sense that there is no room for 2, we have to decide as an individual to enter the gate through Jesus. This mean it is a direct relationship with God, through Jesus. The gate is low that is, it requires our humility in the sense that we must lay down our life before Him and acknowledge that we need Him and only Him can save us. The gate brings us to surrendering to Jesus and He will take us through to the father from there.
John 3:20 - “For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved.”
By Coming to the light of Jesus, we are showing that we love God and we need Him to help us in becoming what God intends for us to be.