Matthew 7:13-14 (KJV)
Enter ye in at the strait gate: for wide is the gate, and broad is the way, that leadeth to destruction, and many there be which go in thereat:  Because strait is the gate, and narrow is the way, which leadeth unto life, and few there be that find it.
John 16:7-10 explains the way in which The Holy Spirit keeps us in the straight and narrow and here is a simple analogy of that work:
In convicting sin, He says to you in love when you’re doing the wrong thing and are proud “Beloved why haven’t you believed in Jesus and that on any matter Jesus is enough and His words are true?” Regarding righteousness, He says to you when you feel unassured of your standing “Beloved, Jesus has justified you by His death on the cross and now He is no longer here, I am here to take his place to keep you in that standard He has set”. Finally, as it concerns Judgment, He says to you when you feel condemned or accused “Beloved don’t yield to the devil, he is already defeated. I’m not the One condemning you. You have a glorious future but he’s is of certain destruction. Resist him and everything he brings your way. You’re more than a conqueror!”.
This is how we must keep ourselves in the straight and narrow because Matthew 7:13 shows it can be missed and it leaves no room for excesses by its uncompromising standard. Just as many have found themselves lost in the jungle of life without a compass or a travel companion we also as believers are susceptible to losing our way when we seem to or assume we can go through life alone without the Holy Spirit. To the one who is yet proud and has refused to receive Jesus, you are not on God’s standard path and judgment looms. But to him who has received Christ’s life, you have been made right and along the path you’ve chosen is life eternal (Proverbs 12:28).