Sant Kabir says:
जब मैं था तब हरि नहीं अब हरि है मैं नाहीं ।प्रेम गली अति सांकरी जामें दो न समाहीं ॥
When there was ‘I’, there was no God, but now, there is only God, and no ‘I’. This universe is a tight place, it can only fit either ‘I’ or ‘God’, both can not fit at the same time.

What Kabir is implying is that our tendency of identifying ourselves with the body (i.e. ‘i’), keeps us away from seeing God. But, once we get over it, we will meet (or identify with) the God that is everywhere, and in the process forget about ‘I’.

This tendency of identifying ourselves with the body is called as अहंकार (Ego), as identifying with the body makes us think, we are the doer of everything in life. We also start to believe that we earned this, we earned that, we did this, we did that, and take credit for everything in life.

But in reality, we are born here to repay (or reap) the prarabdha karma, and whatever we do/achieve in this life is due to the Prarabdha karma and Tri-Gunas (Satva, Rajas, tamas) associated with it. But, due to अहंकार, we start to think everything is achieved/done by us.

As Bhagavad Gita Says:
प्रकृते: क्रियमाणानि गुणै: कर्माणि सर्वश: | अहङ्कारविमूढात्मा कर्ताहमिति मन्यते || (3.27)
All activities are carried out by the tri gunas, but due to the foolishness of Ahankar, we consider ourselves as doers.

Any work is done by considering ourselves as doer results in new karma (agami karma) and becomes the reason for additional birth/death cycles.

So, If there is one thing that we must give up, it is अहंकार. It is difficult but worth every effort.

All the Best!