Chapter 6 Dhyana Yoga Verse 17

Shloka

Yo maam pashyati sarvatra sarvam cha mayi pashyati;
Tasyaaham na pranashyaami sa cha me na pranashyati.

Translation
He who sees Me everywhere and sees everything in Me,
he does not become separated from Me nor do I become separated from him.
Interpretation
After taking about the quietened mind meeting the Brahman this sloka talks about Brahman and its qualities. Lord Krishna says in this sloka that a person who see Him everywhere and sees everything in Him cannot be separated from Him. Not only that Lord Krishna also says that a person who cannot be separated from Him, the Lord Himself will always be with him. That means that a person who sees Lord in everything and who cannot separate himself from the Lord, the Lord always stays with him and never leaves him alone.
Extending Interpretation to Mankind’s Life!
Here we are talking about two things. The first is about  person who sees Lord everywhere and everything inside the Lord. God is the creator of this universe and everything in this world is created by Him. So, when you see anything, you need to see God in that. If you look at a beggar he is also the creation of God and if you look at a millionaire, he is also a creation of God. The only difference is one doesnt have food to eat and the other has everything that he wanted. Though they are the creations of God, its their Karma that makes them a millionaire or a beggar. We are nobody to judge their karma, so we should treat them with the same dignity they deserve as a human being irrespective of what they are. That is what is seeing God everywhere and automatically if God is everywhere in everything in this World is in God.
The second part of the sloka talks about a person not separating himself from God and God not separating Himself from that person. One needs to understand that love for God is beyond all the needs and wants of us, and the best person is the one who worships and respects the God without expecting anything in return. He goes to temple when he feels like meeting the God and not when he has an interview to attend or an exam to clear or a tender to be won. Such people who never expect anything from God are the real devotees of God and God Himself never leaves such people.