"The mountains, the rivers, the whole earth, the entire array of phenomena are all oneself." If you can absorb the essence of this message, there are no activities outside of meditation: you dress in meditation and eat in meditation; you walk, stand, sit, and lie down in meditation; you experience joy, anger, sadness, and happiness in meditation.
If you maintain a feeling of compassion, loving kindness, then something automatically opens your inner door. Through that, you can communicate more easily with other people. And that feeling of warmth creates a kind of openness. You'll find that all human beings are just like you, so you'll be able to relate to them more easily. That gives you a spirit of friendship.