Numbers 1:3From twenty years old and upward, all who are able to go forth for military service in Israel, you and Aaron shall number them by their companies.
The books of Numbers specifically mentioned the age of one's who are qualified to be numbered into the army of God. The age is twenty and above. This number is very significant. It implies the necessity of meeting a requirement who would be numbered and formed into an army, and not general for all. The spiritual implications are:
Strong
The twenty years and above without any upper limit are of male. Meaning, the strong ones among the children of God. This qualification of being strong is needed for God's army.
Overcome the Evil One
1 John 2:13I write to you, fathers, because you know Him who is from the beginning. I write to you, young men, because you have overcome the evil one. I write to you, young children, because you know the Father.
This group of people are those who overcomes the evil one. This needs the growth in the divine life. Only normal and daily spiritual growth can enable one to over the evil one. In fact, only Jesus Christ overcomes the evil one. When the believers grow in life, the life of Jesus in them and being lived out through them makes them an overcomer.
Abiding in the Word of God
1 John 2:14I have written to you, fathers, because you know Him who is from the beginning. I have written to you, young men, because you are strong and the word of God abides in you and you have overcome the evil one.
It is the word of God that makes the believes grow, and it is also the word of God that builds up the believers. This group of believers are the ones who loves the word of God, pursues, eats, enjoys the word of God, and are constituted with the word of God making them abide in the word of God. This is the secret to live an overcoming life and be qualified to be recruited into the army of God.
Not Loving the World
1 John 2:15Do not love the world nor the things in the world. If anyone loves the world, love for the Father is not in him;
This group of believers are those who overcomes the usurpation of Satan and the stupefying effect of the world with all its lust, glitter, and glamour. This also includes those who do not love the present age.
To be formed into the army of God to fight with God against His enemy for His interest on the earth, we must be twenty years and above. This urgently requires our prayer. We are not ignorant of the enemy's strength and strategy. In fact, we are surrounded by him. As the army of God we are protecting and maintaining the testimony of God and fighting against the rebellious forces of Satan. For this reason, we need to grow to be above twenty years of spiritual age.
Lord, cause the growth in me daily; may I grow in life beyond twenty years of age.