The very fact that Paul urges us to dress ourselves with these virtues signifies that none of us has "arrived" spiritually. All of us are flawed, deficient, and weak in some respects. As we yield and develop these virtues, we must be forbearing and forgiving toward our brothers on the basis of Christ's example of forbearance and mercy toward us. The enabling power of God's Spirit is already within us, or this exhortation would be in vain.
It can be done if we will choose to humble ourselves and act when we become aware of the need of a brother or of the church itself. God calls upon us here not merely to act but to do it with affection. In all cases, we must let our heart dictate to our hand, to let our most tender feelings encounter the miseries of those in distress, just as Christ did in descending to clothe Himself in clay. We need to let our feelings be at hand and readily touched that we might open our hands wide in help.
This world has hardened us. We have seen so much arrogance and cruelty that God warns that at the end people will be "without natural affection" (II Timothy 3:3, KJV). We are this end-time generation, and we must go a long way even to start to be like Christ in kindness. But we can do it! Perhaps we can liken beginning to be like this to learning to swim by just "jumping in." Kindness is something that we must develop, and we can do it because God has already enabled us by His Spirit. This fruit is especially sweet tasting and a major factor in producing unity.
Never forget God's character, His example, and this promise He has given to us in Isaiah 54:10: "'For the mountains shall depart and the hills be removed, but My kindness shall not depart from you, nor shall My covenant of peace be removed,' says the Lord, who has mercy on you."