Kṛṣṇa is ultimately instructing Arjuna that sarva-dharmān parityajya mām ekaṁ śaraṇaṁ vraja (BG 18.66): "Your only business is to surrender unto Me, because you are My eternal servant. You rebelled to serve Me. You wanted to live independently in this material world, to become the master, artificially trying to become master. You give up this propensity. You surrender unto Me. Then you will be happy." And Kṛṣṇa assures that ahaṁ tvāṁ sarva-pāpebhyo mokṣayiṣyāmi: "And on your surrender, I will excuse you from all reaction of sinful life."
Why He has said "sinful life"? Because in the material world every activity is sinful, because the main principle is how to become master. Therefore to become master everyone is prepared to do anything, never mind whether sinful or pious. Another meaning is that if we do anything against the order of God, that is sinful. Just like in Bible also there are so many commandments that, "You shall not do this," because they are sinful. A sinful man cannot approach God. That is the verdict of Vedic literature.
- yeṣāṁ anta-gataṁ pāpaṁ
- janānāṁ puṇya-karmaṇām
- te dvandva-moha-nirmuktā
- bhajante māṁ dṛḍha-vratāḥ
- (BG 7.28)
One who is completely free from the reaction of sinful life, he can completely devote in the service of the Lord.
So the common platform is there. God is neither Hindu nor Muslim nor Christian. God is God. God is one. But according to time and climate, condition, the method of approaching God may be different, but the ultimate end is how to love God or how to serve God. One cannot serve anybody without love. In the material world one serves another for matter of money exchange, reward. But serving God is not that. Here it is stated, ahaituky apratihatā. Service of God is without motive. Here in the material world we serve somebody with a motive, for some material gain. But in the spiritual world, to serve God means "It is my duty. I love him. I want to serve Him."