The fruit of the Holy Spirit are love, gentleness, patience, longsuffering and many other things. Yet, there are non Christians whom I have observed practicing this better than me or say some Christians. That makes me wonder what is the role of accepting Christ into our lives or becoming Christians when we don't have the fruits and others have it. Aren't they doing better than us then? Why be Christians? Doesn't the will of God include loving others? And if they do it as non Christians , what is wrong in that..?
Union with Christ teaches that no one, outside of a union with Christ, produces spiritual fruit. Period.
Being joined to Christ, and made one with him, is what produces spiritual fruit. Spiritual fruit can only be produced by the Spirit, which requires that the person be joined to Jesus through the mediation of the Holy Spirit. See John 15. No unsaved person produces spiritual fruit, although they may produce the carnal equivalent at some level.
The unsaved are "in Adam". Christianity is being "in Christ". The believer has been joined or united with Christ, and participates in his resurrection life. Regardless of how it appears, those who are still "in Adam" are spiritually dead, and cannot produce spiritual fruit, because it is a product of spiritual life, which is only gained through union with Christ.
This is not to claim that unsaved people don't have some admirable characteristics sometimes, though. They, too, are made in the image of God and there is some remnant of this image, even in the fallen man. However, if a person is not joined to Christ, they cannot produce spiritual fruit. Cannot. Period.
We would call these admirable things "civic virtue". The person is a good citizen, but he is not producing spiritual fruit. And, the motivation behind his good works may ultimately be selfish.
I'd suggest reading John 15, Romans 5, 6, 1 Corinthians 6, Galatians 5, 1 John 3 in regards to various points I made above.
They need Christ as their center of reference. They can't be anything other than an idolater because if Christ is not their center of reference, then they are an idolater. Their lives are centered on something else, which ultimately proves itself to be worthless.
If families are our idol, they will ultimately let us down. If careers are our idol, they will ultimately let us down. If drugs or sex are our idols, they will ultimately let us down. If success is our idol, it will ultimately let us down. If religion is our idol, it will ultimately let us down, even if others look at us with admiration and we feed off the glory they give to us.