Ephesians 3:16 (NKJV)
16 that He would grant you, according to the riches of His glory, to be strengthened with might through His Spirit in the inner man,
The Spirit is the secret to strength. When we are defiled through contact with the world we become weaker, just like Samson. He was told to not touch any dead thing, nor eat any grape, nor cut his hair, to be like the world around him. As long as he maintained a life of purity, he retained his strength. We are drained of the power of the Holy Spirit when we are polluted with the world. When we return to the Lord, His Word and Spirit, we are cleansed, and strengthened.
None of us are strong enough to walk the walk God has called us to, so it is by the Spirit that we can do this. Strength comes from the inner man. As we live in the Spirit, which means we live in prayer, meditation in the Word, worship and fellowship we will remain strong.
It takes enormous moral and character strength to not do certain things. This strength is ours as we walk in the Spirit. For a leader, it takes great strength to continue carrying the burden of the church and to dis-fellowship those people and influences that threaten to defile the entire body.
All believers will face times when they have to make a stand. The Holy Spirit brings us the strength we need for those times.
To find out how to move more effectively in the Holy Spirit, grab this book – Moving in The Spirit